Based on the information provided in the extracts, it seems that the visual connector builder in Airbyte supports OAuth2.0 authentication with a [refresh token grant type](https://oauth.net/2/grant-types/refresh-token/) and [client credentials grant type](https://oauth.net/2/grant-types/client-credentials/). However, it does not seem to support additional parameters like a Basic Token in the OAuth2.0 flow. The OAuth authentication method in the connector builder requires the client id and client secret and/or a long-lived refresh token to obtain a short-lived access token. If the access token expires, the connection will automatically request a new one. However, the specifics of this flow might not match the exact requirements of your API's authentication process. For complex custom authentication schemes, it's recommended to use the [low-code CDK](https://docs.airbyte.com/connector-development/config-based/low-code-cdk-overview) or [Python CDK](https://docs.airbyte.com/connector-development/cdk-python/). These tools provide more flexibility and control over the authentication process, which might be necessary in your case. In your situation, it seems like you might need to use the Python CDK to build a custom connector that can handle your API's specific OAuth2.0 flow. This would allow you to customize the authentication process to include the Basic Token and handle the access token refresh as required by your API. Here is the link to the Python CDK documentation for more information: [Python CDK](https://docs.airbyte.com/connector-development/cdk-python/).