Thanks Guys i got it to work, i made a link to "has://auth_req/..." and if i click it keychain opens. i didnt get that, im still not sure how the phone know which app to open. But it works. :)
This lines helped me to get it: https://github.com/hiveauth/hive-auth-html/blob/main/index.html#L105-L107
The phone knows what app to open based on protocol.
For the link "has://auth_req/..."
The "has" part is the protocol name. Applications during installation can define in the system which protocol they can handle.