GPTs OpenAPI schema failing

The OpenAI documentation says this about GPTs:

" Custom Actions: You can make third-party APIs available to your GPT by providing details about the endpoints, parameters, and a description about how the model should use it. Actions for GPTs can also be imported from an OpenAPI schema. So if you’ve already built a plugin, you will be able to use your existing plugin manifests to define actions for your GPT."

I am using the same OpenAPI schema as my plugin but on my custom GPT I keep getting 401 Unauthorized status when it makes a call to it. I am using in my CORS origin (set up in Node.js) so I’m not sure why this is happening. My plugin works but not the GPT.

Is anyone else facing this issues or knows the cause?

I looks like I had to add SERVICE_ACCESS_TOKEN. I’m not sure if these can be omitted now with GPTs.