Error in blend_modes library

[talgreen]

Hi,

I'm trying to use the blend_modes library, in order to blend 2 images. I've copied the example code from here:
https://pypi.org/project/blend-modes/

And I'm getting this error:

The blend_modes function "soft_light" received a numpy array with 3 layers for its argument "img_in". The function however expects a 4-layer array representing red, green, blue, and alpha channel for this argument. Please supply a numpy array that includes all 4 layers to the "img_in" argument.

Can someone please help me fix this problem?
Thank you so much,
Tal.