Welcome @tetraizor Happy you are here
If it is a virtual host See this Location of configuration files - Docs - CyberPanel Community
You can also edit in CyberPanel hosting panel as seen screenshot below. CLick vHost COnf
The correct way to rewrite rules if using OLS + CyberPanel is:
Go to https://SERVER_URL:8090/websites/example.com
Click on Rewrite Rules