You are only allowed one AdSense account, you can't get another, and if your Google Account isn't eligible, then you are out of luck.
Have you gone through the steps outlined here: https://yt.be/help/Ta2D ? If yes, you can use this troubleshooting steps to check what happened and what you can do: https://yt.be/help/d8W5 If you still need help after that, reach out to Creator Support: https://yt.be/help/partners