While trying to send an email using Send an email with options action in Power Automate to my email id from a trial account, got the access denied error message.
Check out the wonderful post on sending Approval Emails to external users
The error message –
The cause of this issue was because we were using the trial tenant.
Seems like the resolution is to contact support for an exception till we purchase the license.
Check the below post –
Hope it helps..