Re: Form sends an email, but want to use a list instead
The below flow should give you the details on how to retrieve users from a list and their emails to send an email.
For this example, I have the following list that has three users.

See full flow below. I'll go into each of the actions.

Get items retrieves the users from the list.

Select extracts out the Emails for each user.

Send an email uses the following expression to remove any duplicate emails and join each email with a semi-colon.
join(union(body('Select'), body('Select')), ';')
