Pass the encrypted name of the user in URL from web application. Take native app local session and decrypt the name and compare the user from the account entity. If user matched, create a session for the user and navigate to the home page automatically. This is a workaround solution.
You can refer to this link for native mobile sso configuration – https://medium.com/mendix/mendix-native-mobile-with-sso-3b86b962a899