This is the functions.php file of a custom wordpress theme that a person has given me, the case is that I see strange things and I do not know if it could have malicious code, but I’m not an expert, what do you think?

This is the functions.php file of a custom wordpress theme that a person has given me, the case is that I see strange things and I do not know if it could have malicious code, but I’m not an expert, what do you think?