I can't receive smartphone keys.

If you can't receive smartphone keys, it can be for various reasons. Please check the following:

Did you create an account?
You need to create an account! Make sure you download the Tapkey app and sign in with your Google account or register for a Tapkey ID. Otherwise, you won't be able to get an access permission.

Did you verify your email address?
We automatically send a verification email to the email address you used to sign up for your account. Verifying the email address ensures that you can receive smartphone keys.

Was your email address typed correctly?
Did the person who granted you access type your email address correctly? (Note: It's the no.1 error cause) Please keep in mind that “hugo@gmail.com” is not “hugo@googlemail.de”. 

Do you have internet connectivity?
Last but not least: Check, if your phone has internet connectivity. Maybe you are connected to a Wi-Fi network which requires some login interaction. Public Wi-Fi sometimes requires acceptance of terms of service using the web browser etc.