How to solve the problem of Chinese garbled code of substr_replace () method in PHP?

$str = "Test this method await;
$res = substr_replace ($str," can", 0Power2);
echo $res;
/ / the desired result is: you can use this method a;
/ / but there is garbled
how to solve this problem

Feb.07,2022

PHP document

there is an implementation of mb_substr_replace
mb_substr_replace by billg@microsoft.com

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