Custom Palette not Allowed

[MaxmillianoRivera]

Error message: "Error in pal_validate(pal = pal, dim = dim, flip_axes = flip_axes, rotate_pal = rotate_pal) :
The given palette is not one of the allowed options for bivariate mapping. Please see bi_pal's help file for a list of included palettes."

`custom_pal <- c(
"1-1" = "#1054BF", # low x, low y
"2-1" = "#BF1054", # high x, low y
"1-2" = "#0C3F90", # low x, high y
"2-2" = "#900C3F" # high x, high y
)

bi_pal(pal = custom_pal, dim = 2)

legend = bi_legend(pal = "custom_pal",
dim = 2,
size = 7)`

What's going wrong here?