Aristois

This is already possible with macros.

Esc > Aristois Options > Macros
Add a new one with .say (text) then set it to any key. Below is an image of how you can reproduce your suggestion.

d9ab2b28-7c43-4cc9-9153-586f95feba6b-image.png

It's not meant to go through walls. Other than that, could be anticheat

Disable the setting under Waypoints

Chat overlay in the gui properties