Proxy Request to AWS API Gateway

Hi There,
I want to use cloudflare proxy to AWS Gateway which essentially is pubic API , So i want to avoid Api abuse.

I have seen the tutorial where we can proxy to API Gateway using certificate but my AWS Api Gateway is still public so anyone can by pass and directly hit that API unless i use the API keys to protect and allow cloudflare to use keys and call on behalf, But I am not sure of this setup. Could workers help me with this setup ?

Many thanks,