How to give back in WeChat Pay's successful callback

in Wechat"s payment callback, after I successfully processed it, I directly
return "success"
Wechat reported an error

error example:
transaction_id=4200000217201810305986075380] > < / return_code > < return_msg > < / return_msg > < / xml >]

I change it to xml format and return

return sprintf ("< xml > < return_code > < / return_code > < return_msg > < / return_msg > < / xml >");

Wechat still reported an error

transaction_id=4200000221201810316667479789] > < / return_code > < return_msg > < return_code > < / return_code > < return_msg > < / return_msg > < / xml >]] > < / return_msg > < / xml >]
how to solve

WeChat-Pay Wechat-develops php

Sep.30,2021

does your framework format your output based on your output and modify your output?

add a exit; to try this:

echo <<<XML
<xml>
    <return_code><![CDATA[SUCCESS]]></return_code>
    <return_msg><![CDATA[OK]]></return_msg>
</xml>
XML
;
exit;

return parameters

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