RESTFUL API upload CURL request gets 52 Empty reply from server, please solve it

All the header information has been transmitted, but the file may not have been passed in correctly, but I did not get an error for the need file, but the direct request timed out, every time ~ Is there a solution? Because our system encapsulates Guzzle, we have tried many Guzzle file transfer solutions, but it seems that none of your APIs support it.

Reply content:

All the header information has been transmitted, but the file may not have been passed in correctly, but I did not get an error for the need file, but the direct request timed out, every time ~ Is there a solution? Because our system encapsulates Guzzle, we have tried many Guzzle file transfer solutions, but it seems that none of your APIs support it.