This error is quite specific, and it is probably not a normal permission problem on your side.

The important part is:

Databricks-set rate limit of 0

Databricks is deliberately blocking that model endpoint for your workspace. Databricks documents that a rate limit of 0 effectively disables an endpoint and produces a 403 PERMISSION_DENIED.

Why you're seeing this

Since you said you signed up using AWS, there are two possibilities:

1. You created a Databricks Free Edition workspace, or
2. You created a Databricks trial workspace through AWS Marketplace.

Both have restrictions around model serving/foundation models. Free Edition has explicit Model Serving limitations, including restrictions on certain models and no GPU serving/provisioned throughput.

The similar problem is been resolved here. 

And Databricks documentations also mentions the limitations here.