Follow the steps below:
1 - Start the Thermostat App and select "Account ==> THIRD-PARTY ACCESS" from the main menu
2- Select the text "Open this link and sign in using this emailaddress to view connected applications"
3- The app will show you the "CONSENT LIST" where the applications associated with your Legrand account are listed
On the same page you can revoke the consent of the single application to access your account