I need help with CA's and Firefox

[IlySilence]

Hello github, i need help making a CA for my website, i already tried but my browser gives me a warning saying my website is not safe, is there any solution? I keep getting the error "SEC_ERROR_UNKNOWN_ISSUER", the Firefox versión is 113.0.2, i tried with older FF versions and it works, but if i try it in a recent version i get stuck in that error. Thanks