Please note due to different Android versions/manufacturers, things might be slightly different in places.
Method 1 - Use a computer or phone web browser
- Open [your store url] in an internet browser
- Make sure top-right they are signed into the correct Google account with their approved email
- Accept the invite and click the "download it on Google Play" link
- Click Install the app
Method 2 - Use Google Play Store app
- Open the Google Play Store app
- Click the avatar top-right, this will show the account they are signed into
- If they are not using the approved email, they will need to click the small arrow on the right of the email, they will show the other accounts on the device, they need to then select the other account or Add another account and sign in to the correct account
- Open [your store url] and see if they can install the app
- If the link doesn't work, try searching for Sleepful Drive using the correct account (do not install Sleepful)
Method 3 - Use computer web browser
- Open https://play.google.com/store/apps
- Make sure top-right they are signed into the correct Google account with the approved email
- If they are not signed in to the correct account, click Switch account and change to that account
- Open [your store url] again
- If they can see the app, they should now be able to install it
- Click the Install button and select their phone