How to active Under Attack Mode automatically?

If my site is under attack and i don’t know this, Is there any method to activate Under Attack Mode automatically or show visitor a captcha when they are visiting my site without activing Under Attack Mode Manually

Hi, I don’t think there is (or not that I’m aware of) but if it’s malicious traffic then Cloudflare should filter it anyway.

You could write a script on the server that enables Under Attack Mode if your server load gets too high. The script can also send you an alert so you can disable it when you’re ready.