Tickets are linked to the account which was used to make the purchase.
If you cannot find your tickets on the App it may be that you are signed into the wrong account.
Check which account you're signed into on the website by visiting www.fatsoma.com/settings and checking the email.
Check which account you're signed into on the app by selecting Profile then Settings and checking the email.
If the emails do not match sign out of the app and sign into the account you used to purchase your tickets.
If you are struggling to find your tickets you can find a guide on how to do this here.