First of all, I would like to inform you that the problem is not that I cannot be authenticated or that I cannot set it up. I mainly use the Rest module. So, I tried to use 401 and 403 separately as response types. In the case of a 401 response, it says "Use the body" and the message I responded to is parsed correctly. For 403 responses, the body is "not used." It says. Perhaps for that reason, no matter what response I send, it doesn't have much meaning. However, I confirmed that "Module-Failure-Message" in the 403 response contained the message "rest: Server returned:". It looks like it could be connected by conveying an additional message. If possible, I want the message to be delivered together and appended to the end, even if it responds with a 403 rejection. ex) rest: Server returned: Sorry, Server Reject" Is this possible behavior?