Get a signed upload URL for respondent file uploads
Returns a path-locked signed upload URL for the file-uploads bucket. The viewer calls this before uploading a file so the anon key never needs direct storage write access. Validates that the form exists and is published, and that the session exists.
Request Body
application/jsonRequiredform_idRequired
stringFormat:
"uuid"session_idRequired
stringFormat:
"uuid"file_nameRequired
stringcontent_typeRequired
stringSigned upload URL