sample email template:

Above picture is a default email canvas of powerapp. i have added Cc and Bcc fields .
My case :
Bcc is sourced from 'sharepoint list' and is a combo box , To and Cc are sourced from 'Office365' and are 'regular people picker' fields.
How do the 'send email' combined formulae should be in this case that combines emailid's Bcc, To, Cc,attachments and inserted pictures ?
1. In my case Bcc field item should be a combo box and sourced from 'sharepoint list'
How do i change property of this feild
2. I also need a To and cc fields but these are sourced from Office365.
How can i achieve that.