Result of first test image encoding

you need a black and white image with text

#1 pic

you need a PNG image to encode with

#2 pic

you need a black & white Key image I use the one on this page

https://osric.com/chris/steganography/index.html ( top right corner )

after encoding

#3 pic

Then I save the third image to test the decode

here the decode back now we have a idea what we are looking for and test for

#4 pic