i got error "You are not authorized to execute this request." when use Purchase Flexible Product api

API Spot/Margin API
1

i got error “You are not authorized to execute this request.” when use Purchase Flexible Product api.
payload is in requestBody like productId=TRX001&amount=3294&recvWindow=60000&timestamp=1611715282115&signature=XXXX
The head incuded “X-MBX-APIKEY”

but i got the error “You are not authorized to execute this request.”

2

Are you able to do the same request on the UI version?
Maybe there’s some kind of restriction associated with your account, I would suggest you to contact Customer Support for account research and get more details.