Task: I want to share the ´ Tour to Amsterdam´ document with my buddy karin at karin.iversen@example.com using Gmail.
Steps:
Tap on the three dots menu icon 
Click on the share & export option
Tap on the manage access option
Click on the link option
Tap on the share icon option
Tap on the share icon option
Select the gmail option
Select the recipient id to karin.iversen@example.com
Tap on the send icon