This seems like a perfect job for me. I own GTA V and have played it before, and I have also played on FiveM/Rage servers before.
JavaScript/NodeJS and Lua are scripting languages I have a lot of experience with, since I have made some plugins for Garry's Mod before (Lua) and have made Discord bots with NodeJS before.
I also have experience with SQL (mostly SQLite, but MySQL is similar and I have also used MySQL before), so that is nice too.
In conclusion, I think you should pick me since I have experience with the game and making game addons, and I also have experience with the scripting languages skills you require.
PS, let me know if you would like specific milestones for the project and we can change them.