How do i log into the runescape 3 with my normal jagex accounts?
example account name is "example123" how do i log in with just that is it still possible or do you need to combine accounts with a jagex account now?

I use my account “xxxxx” to log in on rs3

Try logging into site and see if it asks you to do something.

Should just be able to open the rs3 app and login, I would imagine. Same with osrs.

No one needs to upgrade their accounts. It's just at a certain point and new account had to be a jagex account, but old accounts aren't force to convert. At least not yet.