Your target audience: Understands and wants WebAuthn, and is capable of using your API - and is incapable of writing their own layer, and is security minded enough to want WebAuthn but also doesn't want to use an existing solution like Keycloak or Identity Server.

Create a target customer profile and see where it leads you.

Also your landing page needs work. Pricing should be an anchor in the top right -- its just as important as your documentation. I'm not going to browse documentation for a service I could never afford to use (or one where I'm forced to Contact Sales, among other possible steps before getting there.)