The English version of Persona 5 Royal is now supported by the Mod Compendium. At least for the USA copy, but PAL support is planned.
You can refer to the updated P5R Modding Guide for details on how to do this yourself. You need to be on either firmware 5.05, 6.72 or 7.02– no exceptions! The lower the better.
There’s a few mods you can try out already at amicitia.github.io such as the P5 Mod Menu.