how to send an email from power apps code example

Example: powerapps send email from other account

Office365Outlook.SendEmailV2(toEmail, subject, body, {From: fromEmail});

This parameter allows you to send Email on behalf of the others within 
your Office 365 tenant.
Doing it in this way requires Mailbox permission from the other User Account.
To give permission >> https://docs.microsoft.com/pt-pt/microsoft-365/admin/add-users/give-mailbox-permissions-to-another-user?redirectSourcePath=%252fen-us%252farticle%252fgive-mailbox-permissions-to-another-user-in-office-365-admin-help-1dbcf12f-a9de-4d1d-b0b3-a227f8a736d8&view=o365-worldwide