argument 3 matches multiple formal arguments

[jasoncrucify]

hi,
Error in RunHarmony.Seurat(object = merged_seurat, group.by.var = "orig.ident", :
argument 3 matches multiple formal arguments

when I run seurat <- harmony::RunHarmony(object =seurat, group.by.vars="orig.ident",
reduction = "pca", assay.use="RNA", plot_convergence = T, verbose = T)

when I removed reduction = "pca", it worked, but the harmony dimension drops to 4, no idea what happened, it seems the harmony integration worked

seurat was from a merged seurat object from two seurat object by merging a group of sample of each.

do you know what happened the error?

many thanks