Cause
event_options only accepts milestone.due_soon and deadline.due_soon, each with threshold_days, and the type must be in events.
What to do
Fix the options.
application/problem+json
{
"type": "https://masnet.com/developers/errors/invalid_event_options",
"title": "Invalid event options",
"status": 400,
"detail": "...",
"code": "invalid_event_options",
"correlation_id": "..."
}