Try adding a condition to PHP01.php that checks where it is being called from, this ensures that you only echo the code if the file PHP01.php call is PHP01.php
In addition, it is better if you add functions to your own file, if necessary, to save certain functions that are present, for example, in PHP01.php , you can add include 'function01.php'; , and it will have this function divided between two files.
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