TooManyRequest error 503

I need to identify in real time who is accessing too much (my site) I work with Amazon products API and it limits the amount of access in a short period of time, I’ve tried to block known User-Agents but it’s not working, I need to know who ( a bot) is consuming all my requests, I use the free version of cloudflare.

For good background, I’d start here, https://support.cloudflare.com/hc/en-us/categories/200275228, that’ll show all firewall documentation. Next, to deal with the attack, I’d review

You should enable Under Attack Mode, https://support.cloudflare.com/hc/en-us/articles/200170206-How-do-I-enable-I-m-Under-Attack-mode-. And, if you continue to have issues, look into Bot Fight Mode, https://support.cloudflare.com/hc/en-us/articles/360035387431-Understanding-Bot-Fight-Mode.