email address for extension's outgoing messages

I am sure the answer is easy but I cannot find it. How do I set the "sender" email address for the automated notifications that the OS Services Booking component. When someone registers, I'd like the notifications to be sent from an address that I choose. Where do I change this setting so that outgoing emails show the  sender email address that I've chosen? Currently, I can only change the sender by modifying the Joomla global PHP mail setting.

Currently, OS Services Booking uses Joomla Mail Setting to send email, therefore, it's impossible to change Sender email address
Thanks
Dam