How to set tlsClientAuth?

I need to handle request regarding the tlsClientAuth property, only TLS Client Certificate from my own CA are allowed.

But tlsClientAuth is not set, and the docs tells my that this is “Only set when using Cloudflare Access or API Shield (mTLS).” So I added Cloudflare Access in front of my worker, but this property is still not set.

docs developers.Cloudflare .com /workers/ runtime-apis/ request