OpenAI-compat: OpenAIConnection base_url /v1, not AzureOpenAIConnection api_base

Working config (OpenAIConnection, base_url /v1)

Prompt flow already has OpenAIConnection (type: open_ai). A Chat Completions host whose public catalog is GET https://api.pzero.studio/v1/models (no key) fits that type if base_url is set. The example openai.yml leaves base_url empty, which hits api.openai.com.

$schema: https://azuremlschemas.azureedge.net/promptflow/latest/OpenAIConnection.schema.json
name: pzero
type: open_ai
api_key: <Bearer key for that host>
base_url: https://api.pzero.studio/v1

LLM tool: Chat (not Completion). Model is a catalog id from that /v1/models list, for example deepseek-v4-flash.

Do not use AzureOpenAIConnection / type: azure_open_ai. That type's api_base is an Azure endpoint, not this host. OpenAIConnection uses base_url, not api_base.

Not asking for a first-party provider. open_ai plus base_url is enough.