PersonWantsOrg "Method MakeDecision was not found."

Hello! 

1IM 8.1 

I need approve request over API. 

When I do request 

"https://server/api/entity/PersonWantsOrg/dd74829c-73fa-4d1e-b8ae-059f517c783e/method/MakeDecision" I get error: 

{"responseStatus":{"errorCode":"NotFound","message":"Method MakeDecision was not found.","errors":[]}}

User assigned to Common_StartCustomizerMethods program function.

How I can fix it?