Construct email address from Azure Sentinel Incident Alert

Hi Friends,

I would like to construct an email address to send an email to the user account that generates an incident by concatenating the "Account Name" + "@" + ""UPNSuffix" through a concat function.

I would like to place the address generated in the "To:" field of an "Outlook Send Message" action in my logic app. And I have been struggling to do this now for days. 

Can someone please help or point me to way to construct this address from an incident please....

Thank you,

-egal