Generac GP15000E Recall
Generac is recalling certain models of the GP15000E.
The recalled generators’ fuel tank can fail to vent adequately from the rollover valve, causing the gas tank to build up excess pressure and expel fuel when opened, posing fire and burn hazards.
The portable generators that are recalled are eligible for a rollover valve repair kit that Generac will send to you if you ask them.
I don't know what the "repair kit" consists of considering that the entire rollover valve retails for maybe $15.
https://www.cpsc.gov/Recalls/2023/Generac-Recalls-Portable-Generators-Due-to-Serious-Fire-and-Burn-Hazards
https://www.generac.com/gpenhancements