Starting with fillet edge

Hi everyone! I think that my question is a bit easy to solve, but I´m a bit lost. Want to make a chamfer to a “box 2pt” but I can´t get the chamfer in the edge I want. Don´t know how to change or select the edge in wich I want to apply the command.
I upload an image with the result (in red) and what I would like (in yellow).

Thanks a lot for your help.

Does this help? (5.5 KB)

Yesssss…It works perfectly. Thank U :upside_down_face: