A magic login link replaces the use of a password to log into the app. When you sign in with your email, the magic link will be sent to your email which will automatically open the app and log you in.
Make sure to open the magic link using the mobile device that you want to login with.
If the magic links are not working for you, then:
Open the email that you received
Below the login button, there is a 6-digit login code
Open the app
Press "Login"
Enter your email address
Press "Enter code" at the bottom of the screen
Enter your 6 digit code and press verify
Note that for security reasons, magic login links are only valid once and expire after a limited time.