When I am on PAD website, where I can see my cloud flows and desktop flows, I tried to open my app throught Desktop flows tab because I couldn't see flows that I created some time ago. Then my app opens saying that I need to log in (even if I am already log in).When I write my password I receive this error

What could cause this error? I updated app and it's the same.Here's the full error message;
Request Id: 1a49ac0b-2a7d-46b3-a76b-981bec9dde00
Correlation Id: 3c636b85-f697-4112-9b2c-c94371f73346
Timestamp: 2021-08-05T07:55:17Z
Message: AADSTS50020: User account 'My_Email' from identity provider 'live.com' does not exist in tenant 'Microsoft Services' and cannot access the application '386ce8c0-7421-48c9-a1df-2a532400339f'(Power Automate Desktop For Windows) in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different Azure Active Directory user account.
Thanks for help in advance!