This looks like the way to go https://www.amazon.com/Magicfour-Replacement-Water-Faster-Flowing/dp/B07ZT3GPKR/ref=mp_s_a_1_1_sspa?dchild=1&keywords=gas+can+vent+caps&qid=1607035455&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExT0VEN1pKS1VIQ01UJmVuY3J5cHRlZElkPUEwMDk0MDA1MUxDOFlXMUhPVzdTTSZlbmNyeXB0ZWRBZElkPUEwMzIwMTYxMU80VTNQSzdWSldBQiZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl