You sign in with your email and the password you chose when you signed up. The same details work on your phone and on a computer.
Open the login page your coach sent you
Open the Marrow app, or go to the login page your coach shared. This is where you start every time. Nothing to install if you do not want to. The same link works on your phone and on a computer.
Enter the email your coach invited
Type the email address your coach used to invite you. It has to match, because that is the email tied to your training. If you are not sure which one your coach used, check your inbox for the invite from Marrow and use that address.
Enter the password you chose
You set your password when you opened your invite and created your account. That password is how you get in every time. Nothing is emailed to you to let you in, so there is no link to wait for.
You can change your password whenever you like from your own settings, once you are signed in.
Add the app to your home screen
So you are not signing in from a browser tab every morning, add Marrow to your home screen. Open it on your phone, tap the share button, and pick Add to Home Screen. After that it opens like any other app, one tap, straight to today's session.