

OliveTin is exactly what I wanted (tbh, was heard to read with your crammed together text, thanks as well @bonenode@piefed.social for helping me spot it! )
Keycloak, Pocket ID, Authentik, anything of the sort does sort great as well! Thanks for the recommendation for the follow-up step! :-)


There is also Postmarket OS which I saw mentioned that they were able to even reformat iPhones (F Apple products) https://wiki.postmarketos.org/wiki/Devices
But never buy Apple products.