API POST request fails if no Provider/no Auto Provider allowed

[SpecialAro]

Bug description
Previously, when using version v0.3.0.7 I could make a request using the API at http://localhost:1337/v1/chat/completions I could easily not specify the Provider and at each request, a different provider was used. Now, using the latest version, if I don't specify the provider when making the POST call the request fails. Specifying a provider allows me to get a successful POST request, though, it doesn't allow rotation of providers (that was present in v0.3.0.7)

Steps to reproduce:

1. Use v0.3.0.7
2. Make POST request WITHOUT specifying "provider" in body
3. Watch that providers rotate at each request (which is the behaviour I intend)
   --
4. Use latest tag
5. Make POST request WITHOUT specifying "provider" in body
6. POST Request fails (this is also an issue by itself)
7. Make POST request specifying "provider" in body
8. POST Request succeeds but does not allow me to rotate providers at each request (as in v0.3.0.7)

Let me know if you need further clarification or help in solving this.

Thank you very much upfront! 😄