Can't change "read the rest of this entry" in theme

Hi, I have Magazine Basic theme installed. I want to change the “read more” to custom, but i can’t do it. The thing is even in WP Theme in loop.php it is “read more”, but it shows up “read the rest of this entry”. As a conclusion, this tag text should in WP Engine, right? Or I am wrong. Seems the problem is with theme code. Before I used built-in theme excerpt and could change it to custom in functions.php, but now I put <–more–> tag in my post and nothing happens instead of “read the rest of this entry”. Below is the of loop.php
https://pastebin.com/Z8xdeXpa
and functions.php https://pastebin.com/1i3LPByV
I really need your help and will appreciate it!