For iOS do we need to add associated domain capability?

[chunsfire]

In order to implement webauthn passkey registration or authentication flow, iOS mandates to have associated domain capability added. This is due to underlying ASAuthorization framework.

So does this package also needs associated domain capability enabled & added in the project?

[CatMLily]

You should config your own associated domain in your project and server.
First, you should add your domain in your xcode project.

And then you should create a apple-app-site-association file in your domain server.
You can check if apple'cdn has catched your apple-app-site-association config via this link https://app-site-association.cdn-apple.com/a/v1/your.domain.name

reference: https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_developer_associated-domains?language=objc