Front derailleur change
I think probably a Shimano Tourney top-pull derailleur that can accommodate the chainring sizes you have will work. You can see the basic specifications here to help pick out the correct model.

Front derailleurs are very basic mechanically and don't 'stop working' unless they actually physically break. It's possible you simply have the derailleur badly adjusted, or there is something wrong with the cable or housing.

Inspect the cable run from the shifter to the derailleur and make sure the housing is properly in the shifter body and all frame stops.

Disconnect the cable, tension the cable manually and work the shifter. Check the cable pull in and let out smoothly and does not hang up in the housing.

Verify the derailleur will swing from the smallest to largest chainring (it helps if you can pop the chain out of the cage).

If all that checks out, follow a front derailleur adjustment procedure. Park Tool has a good page and video with step-by-step guidance.