Redirect to app (`appUrlOpen`) from InAppBrowser using WebView

Capacitor
1

Disclaimer: It does work when using SystemBrowser instead of WebView, but that is not my intention.

In a project I am using angular-oauth2-oidc for authentication against my keycloak server.
I thought of using the @capacitor/inappbrowser to open the authentication page of my keycloak server in app, for it to look seamless (no url bar, buttons etc)
To do this I configured my oAuthService like this:

 private getAuthConfig(account: Account): AuthConfig {
    let redirectUrl = window.location.origin;
    if (Capacitor.isNativePlatform()) {
      redirectUrl = 'app://myapp/login-redirect';
    }
    return {
      issuer: account.auth.url + '/realms/' + account.auth.realm,
      redirectUri: Capacitor.isNativePlatform() ? redirectUrl : window.location.origin,
      logoutUrl: window.location.origin,
      clientId: account.auth.clientId,
      responseType: 'code',
      oidc: true,
      scope: 'openid offline_access',
      showDebugInformation: true,
      openUri: (uri) => {
        InAppBrowser.openInWebView({
          url: uri,
          options: DefaultWebViewOptions,
        });
      },
    };
  }

This does open the keycloak login page.
After login it also redirects to the given address app://myapp/login-redirect which is registered for the app. But instead of opening the app and trigger the appUrlOpen callback, the WebView tries to actually display app://myapp/login-redirect ending in an error.

image
image378×395 17.6 KB

As soon as I switch to system browser, it works as desired. It seems that the app cannot be opened/called by the webview. Is there some configuration missing for the webview or is the InAppBrowser using a webView not able to?

Update:
I could get a glimpse of the actual error page showing ERR_UNKNOWN_URL_SCHEME, meaning that the webview indeed is not able to process the redirect.