We recommend you use the Alexa web app (https://alexa.amazon.com) to remove your access to your "... with Netatmo" connected home.
Follow the following instructions:
1 - in the main menu, select "Skills",
2 - select "Legrand Home + Control" and click on "deactivate skill",
3 - in the main menu, select "Connected home" and click on "Forget" device by device or otherwise "Forget all" (N.B. all your Legrand or other brand products linked to Amazon Alexa will be forgotten).
Your access to the connected home via Amazon Alexa is removed