Hi @AndyCoin11 and @John6666 !
Indeed, this is a very new feature on the Hugging Face Hub, and we’re in the process of updating the documentation to surface it.
There was a brief period of time where users were prompted to buy credits, but those credits could not apply to extend ZeroGPU quota.
That issue has been fixed and purchasing credits should allow you to use ZeroGPU Spaces over your included quota now.
Let us know if you have any additional issues!