By error, I create it in Thunderbird and I want to suppress it.

You cannot 'suppress' an account. Are you saying you set up a new Microsoft account by error in Thunderbird, and now you want to delete it?

If so, at the top right of the Thunderbird window, click the menu button > Options > Account Settings

Select the account to be deleted in the left pane.

Choose 'Remove Account' from the 'Account Actions' drop-down menu at the bottom of the left pane.

Thank you, Chris, for this bright answer. For a French, to suppress = to delete. But you can aswer me in French if needed. In the Thunderbird version 78.6.1, there is not "at the top right of the Thunderbird window, click the menu button > Options > Account Settings". Please see the pic.

I must add this pic...

In the Thunderbird version 78.6.1, there is not "at the top right of the Thunderbird window, click the menu button > Options > Account Settings".

Looking at your screenshot, the mouse pointer hovers exactly over the app menu button. It should have been click the menu button > Account Settings

I'm certain you'll figure out what 'Account Settings' is in French.

Please have a look on the second pic. There is no way to configure any list of accounts, (even in French). I don't have any doubt concerning the good understanding you may have with the pics I sent. The mouse arrow means what is shown when I click on "Options".

Look for 'Account Settings' in the first screenshot. Can't be that hard.

"Can't be that hard". What is the utility of this comment ? To reinforce your ego ? To prove something ?

However, I finally found where to suppress (For Chris : to delete) the account, I put a last pic for others. Best regards