I understand that your account is not present in your tenant. To resolve this issue, you need to add the user account as an external user in the tenant.
Contact your global administrator in your account to add external user. Follow below steps:
1.Navigate to the Microsoft Entra Id blade.
2.Click on the 'Users' blade.
3.Click on the 'New guest user' button.
4.Fill in the required details for the new user and invite them to the tenant.
Once you accept the invitation and your account is created in the tenant, now you can access the application using your account.
Hope this helps. Do let us know if you have any further queries.
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Thanks,
B. Siri Chandana.