Im trying to make a shotgun that pushes the player backwards when shot

Godot Version

Godot 4

Question

Im trying to make a shotgun that has a very high recoil. I mean that the recoil is high enough to push the player through the air

That depends on your current code structure. Is your player a CharacterBody3D? Then when you shoot, you can just add some velocity in the opposite direction of the shot, before you call move_and_slide().

my code structure is the character body 3d player movement template with some lines of code for the shotgun

Great. Did you try my suggestion then? It should work.