When I try and open it it says requires 'supermartijn642configlib 1.1.6 or above' when I have already downloaded 'supermartijn642corelib-1.1.7-forge-mc1.19.4'.

That is asking for my config library, not core library.

Thank you for helping me as I didnt realise that you had to download both. Btw the mod is awesome.