Sharing a Google Drive file without sending notification email

On step 2, when sharing the file with the new user, you'll be using the permissions.insert() API call. You'll want to specify the sendNotificationEmails=false parameter along with this call to suppress the email notification.

In the Google Drive API V3 with permissions.create() it has changed to singular: sendNotificationEmail=false

In a POST request it would be like this:

https://www.googleapis.com/drive/v3/files/*FILEID*/permissions?sendNotificationEmail=false