RV Lock is a very popular replacement option. You can find them on Amazon here:https://www.amazon.com/s?k=rv+lock&crid=35HBN0BAF1MQJ&sprefix=rv+lock%2Caps%2C107&ref=nb_sb_noss_1
Just be sure to measure your current lock opening to see if it fits before ordering.
If you simply want to replace it with the same lock you can contact your closest Keystone dealer and they will hook you up.