Firewall rule does not work (DDOS)

Hello guys
I have 100% requests DDOS fom user agent :
Mozilla/5.0 (Linux; Android 8.1.0; DRA-L21) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.101 Mobile Safari/537.36
How can I ban user agnet coming from LINUX ?
I made rules user agent contains “Linux” and it does not work …

A post was merged into an existing topic: Can’t resist DDOS even on under attack mode