I'm trying to analyze FACS data using the flowcore package and I'm getting an error when trying to generate the gating set saying the GatinSet function can't be found.

fs <- read.flowSet(path = "~/Library/CloudStorage/Box-Box/UlitskyLab/Projects/Sanofi_LNPs/Experiments/Luciferase/15_7_24_transfection_LNPs/",pattern = ".fcs",alter.names = T)
pData(fs)[1:3,]
#change names 
colnames(fs)
colnames(fs)[colnames(fs)=="FL5.A"] <- "GFP"
colnames(fs)[colnames(fs)=="FL2.A"] <- "DNA content"
#gates
gs <- GatingSet(fs)

# gs <- GatingSet(fs)
Error in GatingSet(fs) : could not find function "GatingSet"
# please also include the results of running the following in an R session 

sessionInfo( )
R version 4.4.1 (2024-06-14)
Platform: x86_64-apple-darwin20
Running under: macOS 15.6.1

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.4-x86_64/Resources/lib/libRlapack.dylib;  LAPACK version 3.12.0

Random number generation:
 RNG:     Mersenne-Twister 
 Normal:  Inversion 
 Sample:  Rounding 

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: Asia/Jerusalem
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] flowCore_2.16.0     dbplyr_2.5.0        BiocManager_1.30.26

loaded via a namespace (and not attached):
 [1] gtable_0.3.6        dplyr_1.1.4         compiler_4.4.1      ggsignif_0.6.4      tidyselect_1.2.1    Biobase_2.64.0      cytolib_2.16.0      tidyr_1.3.1         scales_1.4.0        RProtoBufLib_2.16.0 ggplot2_4.0.0      
[12] R6_2.6.1            ggpubr_0.6.1        generics_0.1.4      Formula_1.2-5       BiocGenerics_0.50.0 backports_1.5.0     tibble_3.3.0        car_3.1-3           munsell_0.5.1       DBI_1.2.3           pillar_1.11.1      
[23] rlang_1.1.6         utf8_1.2.6          broom_1.0.10        cli_3.6.5           magrittr_2.0.4      grid_4.4.1          rstudioapi_0.17.1   lifecycle_1.0.4     S4Vectors_0.42.1    vctrs_0.6.5         rstatix_0.7.2      
[34] glue_1.8.0          stats4_4.4.1        abind_1.4-8         carData_3.0-5       fansi_1.0.6         colorspace_2.1-2    purrr_1.1.0         matrixStats_1.5.0   tools_4.4.1         pkgconfig_2.0.3

GatingSet isn't a function in flowCore. It is however in flowWorkspace, which you would need to load first.