Missing Function in scMAGeCK

[taffy-miao]

Hi Team, I'm now using the scMAGeCK package, but when I follow the code ps_demo.R, the following code encountered some error:
eff_object <- scmageck_eff_estimate(rds_object, bc_frame, perturb_gene='TP53', non_target_ctrl = 'NonTargetingControlGuideForHuman')

Error in scmageck_eff_estimate(rds_object, bc_frame, perturb_gene = "TP53", : could not find function "scmageck_eff_estimate"

Is there some mistakes in the package or did I do it wrong?