This sounds like another similar thread, which I ran into while trying to find workarounds myself. I posted what I ended up doing here: Gamepad Menu Navigation Issues - Programming & Scripting - Unreal Engine Forums
(Not sure on etiquette of copy/pasting the same post, so I’ll just link it.)
TLDR is - if you put the input button you want to use in the player controller or pawn, and have it set a variable to true when pressed, and then re-setting that variable to false when released, you can cast to the player with your widget each frame, and run that through a branch tied to that variable.
Then, you can have that go through a sequence, each one going to a new branch, which is tied to “Is Hovered” which is then tied to each button you want to use.
These branches then only output on “true” “Is Hovered” responses from the buttons, and feed into whatever you want that button to do.
Hopefully this is kinda what you’re looking for? The other thread was a bit more specific about how they were hoping to use this spoofing of mouse clicks, I’m assuming it’s for a menu widget or something similar.