MixscapeLDA error

[TsviyaOlender]

Dear Seurat team
I am getting an error when I try to apply LDA dimensionality reduction.
My seurat object includes 282 NT cells and 79 KO cells.
The command I am trying to use is:
sub <- MixscapeLDA(
object = sub,
assay = "RNA",
pc.assay = "PRTB",
labels = "targetGene",
nt.label = "NT",
npcs = 20,
logfc.threshold = 0.1,
verbose = F)
and the error is:
Error in DefaultAssay<-.Seurat(object = *tmp*, value = pc.assay) :
Cannot find assay prtbpca

Can you please help me to resolve this error?

Many thanks
Tsviya