Perpendicular Surface blend/fillet

Hi all - brand new here, so apologies in advance for the entry level type question. I have been using Shapr3D for a couple months now and am looking to blend two perpendicular surfaces together with an internal fillet/radius. Can’t quite seem to get the sequence right or I am chasing down the wrong rabbit hole. Pictures attached is what I have (grey part) and what I am looking to recreate (purple part).

Can anyone help walk me through this step by step?

and second pic

On your first picture, is the gray wall and the floor separate parts? If so, you need to combine the parts into one using Union first. Then you can do the fillet radius.

TigerMike - thank you much!!! That is exactly what it was, appreciate you.