It was normal for me to pay with an on file card before. After a period of time, the payment was unsuccessful. I just don’t know why. The errors reported are as follows：
“category=INVALID_REQUEST_ERROR, code=NOT_FOUND, detail=Did not find matching card, field=source_id]”
If you call RetrieveCustomer with the customer_id does it return the card_id that you passed in as the source_id? 
When I pay, I send source_id like “ccof:”
Is this a problem? If so, why is it
No, sending the whole card_id like ccof:8aqMsIYrLHkwQdJk3GB is expected. What’s your application ID?
This is sq0idp-nLHuyQkjmpYX0S8uYZ2IYQ, this kind of problem has just occurred.
What did you pass in as the source_id?