Google AI Studio Billing

Need a help for Google AI Studio
I have a billing account active and a project is associated with it.
Let me add more details, I have a project in GCP name XX-uat, inside this project i have VMs and other resources which are using budget. To track this I have created a budget with name XX-uat-budget and added threshold to it to take appropiate actions.
Now in the same project I want to ai studio. in this https://aistudio.google.com/ when I import project, i am asked to again add billing tier information and buy credits. Cannot be sync the project billing here