Forcing atari2600 to use analog stick on ps3 controller

I’m trying to get atari 2600 to use the analog stick on the ps3 controller, I’m just not sure what to put in /opt/retropie/configs/atari2600

I did figure out how to get into the retroarch menu during a game and change the mapping there. If I do that it lets me use either the dpad or the stick for directions in the game, but it doesn’t save the settings so I have to remap the up, down, left, and right to the analog stick everytime.

Any help would be appreciated!