You can install scMEGA via below commands:

# Install devtools
if (!requireNamespace("devtools", quietly = TRUE))
    install.packages("devtools")

# First install Seurate v5
devtools::install_github("satijalab/seurat", "seurat5", upgrade='always')
## Skipping install of 'Seurat' from a github remote, the SHA1 (f6ec683a) has not changed since last install.
##   Use `force = TRUE` to force installation
# Install scMEGA
devtools::install_github("CostaLab/scMEGA")
## Skipping install of 'scMEGA' from a github remote, the SHA1 (fb5e54d9) has not changed since last install.
##   Use `force = TRUE` to force installation
# Check session information
sessionInfo()
## R version 4.2.1 (2022-06-23)
## Platform: x86_64-apple-darwin17.0 (64-bit)
## Running under: macOS Ventura 13.4.1
## 
## Matrix products: default
## LAPACK: /Library/Frameworks/R.framework/Versions/4.2/Resources/lib/libRlapack.dylib
## 
## locale:
## [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
## [1] scMEGA_1.0.1
## 
## loaded via a namespace (and not attached):
##   [1] utf8_1.2.3                  spatstat.explore_3.2-1      reticulate_1.30             tidyselect_1.2.0           
##   [5] htmlwidgets_1.6.2           grid_4.2.1                  ranger_0.14.1               Rtsne_0.16                 
##   [9] devtools_2.4.5              munsell_0.5.0               destiny_3.10.0              codetools_0.2-19           
##  [13] ica_1.0-3                   future_1.33.0               miniUI_0.1.1.1              withr_2.5.0                
##  [17] spatstat.random_3.1-5       colorspace_2.1-0            progressr_0.13.0            Biobase_2.58.0             
##  [21] knitr_1.43                  rstudioapi_0.14             Seurat_4.9.9.9058           stats4_4.2.1               
##  [25] SingleCellExperiment_1.20.1 ROCR_1.0-11                 robustbase_0.95-0           vcd_1.4-11                 
##  [29] tensor_1.5                  VIM_6.2.2                   TTR_0.24.3                  listenv_0.9.0              
##  [33] MatrixGenerics_1.10.0       GenomeInfoDbData_1.2.9      polyclip_1.10-4             farver_2.1.1               
##  [37] rprojroot_2.0.3             parallelly_1.36.0           vctrs_0.6.3                 generics_0.1.3             
##  [41] xfun_0.39                   ggthemes_4.2.4              R6_2.5.1                    GenomeInfoDb_1.34.9        
##  [45] graphlayouts_1.0.0          RcppEigen_0.3.3.9.3         cachem_1.0.8                bitops_1.0-7               
##  [49] spatstat.utils_3.0-3        DelayedArray_0.24.0         promises_1.2.0.1            scales_1.2.1               
##  [53] ggraph_2.1.0                nnet_7.3-18                 gtable_0.3.3                globals_0.16.2             
##  [57] processx_3.8.2              goftest_1.2-3               spam_2.9-1                  tidygraph_1.2.3            
##  [61] rlang_1.1.1                 scatterplot3d_0.3-44        splines_4.2.1               lazyeval_0.2.2             
##  [65] hexbin_1.28.2               spatstat.geom_3.2-1         yaml_2.3.7                  reshape2_1.4.4             
##  [69] abind_1.4-5                 httpuv_1.6.11               usethis_2.1.6               tools_4.2.1                
##  [73] ggplot2_3.4.2               ellipsis_0.3.2              jquerylib_0.1.4             RColorBrewer_1.1-3         
##  [77] proxy_0.4-27                BiocGenerics_0.44.0         sessioninfo_1.2.2           ggridges_0.5.4             
##  [81] Rcpp_1.0.11                 plyr_1.8.8                  zlibbioc_1.44.0             purrr_1.0.1                
##  [85] RCurl_1.98-1.12             prettyunits_1.1.1           ps_1.7.5                    deldir_1.0-9               
##  [89] pbapply_1.7-0               viridis_0.6.4               urlchecker_1.0.1            cowplot_1.1.1              
##  [93] S4Vectors_0.36.2            zoo_1.8-12                  SeuratObject_4.9.9.9091     SummarizedExperiment_1.28.0
##  [97] ggrepel_0.9.3               cluster_2.1.4               fs_1.6.3                    factoextra_1.0.7           
## [101] magrittr_2.0.3              data.table_1.14.8           RSpectra_0.16-1             scattermore_1.2            
## [105] lmtest_0.9-40               RANN_2.6.1                  pcaMethods_1.88.0           fitdistrplus_1.1-11        
## [109] matrixStats_1.0.0           pkgload_1.3.2.1             patchwork_1.1.2             mime_0.12                  
## [113] evaluate_0.21               xtable_1.8-4                smoother_1.1                fastDummies_1.6.3          
## [117] IRanges_2.32.0              gridExtra_2.3               compiler_4.2.1              tibble_3.2.1               
## [121] crayon_1.5.2                KernSmooth_2.23-20          htmltools_0.5.5             later_1.3.1                
## [125] tidyr_1.3.0                 DBI_1.1.3                   tweenr_2.0.2                MASS_7.3-58.3              
## [129] boot_1.3-28.1               Matrix_1.6-0                car_3.1-2                   cli_3.6.1                  
## [133] parallel_4.2.1              dotCall64_1.0-2             igraph_1.5.0.1              GenomicRanges_1.50.2       
## [137] pkgconfig_2.0.3             laeken_0.5.2                sp_2.0-0                    plotly_4.10.2              
## [141] spatstat.sparse_3.0-1       bslib_0.5.0                 XVector_0.38.0              callr_3.7.3                
## [145] stringr_1.5.0               digest_0.6.33               sctransform_0.3.5           RcppAnnoy_0.0.21           
## [149] spatstat.data_3.0-1         rmarkdown_2.23              leiden_0.4.3                uwot_0.1.16                
## [153] curl_5.0.1                  shiny_1.7.4                 ggplot.multistats_1.0.0     lifecycle_1.0.3            
## [157] nlme_3.1-162                jsonlite_1.8.7              carData_3.0-5               desc_1.4.2                 
## [161] viridisLite_0.4.2           fansi_1.0.4                 pillar_1.9.0                lattice_0.20-45            
## [165] pkgbuild_1.4.0              fastmap_1.1.1               httr_1.4.6                  DEoptimR_1.0-11            
## [169] survival_3.5-5              remotes_2.4.2               glue_1.6.2                  xts_0.13.0                 
## [173] png_0.1-8                   profvis_0.3.7               sass_0.4.7                  ggforce_0.4.1              
## [177] class_7.3-21                stringi_1.7.12              RcppHNSW_0.4.1              memoise_2.0.1              
## [181] dplyr_1.1.2                 irlba_2.3.5.1               e1071_1.7-13                future.apply_1.11.0