Cause
The modality is not identified or confidential, is not among those the version accepts, or allowed_modalities is empty. The anonymous modality does not exist.
What to do
Use a modality the version accepts.
application/problem+json
{
"type": "https://masnet.com/developers/errors/unsupported_modality",
"title": "Unsupported modality",
"status": 422,
"detail": "...",
"code": "unsupported_modality",
"correlation_id": "..."
}