Migrate Real-Time feature helps you migrate the files/attachments in real-time i.e. the files/attachments will be migrated automatically once they are uploaded to record. 
- Enable File Migration trigger - To enable the automatic migration of files/attachments, turn on this toggle.
- Filter files by adding SOQL filter conditions - You can filter files that are to be migrated before they are migrated to Amazon s3 by adding SOQL conditions in the text area.
- Selected object - Only selected objects will be consider for migrate files to Amazon S3.
- Delete Files After Upload - Turn this toggle on when you want to delete the file from Salesforce after migrating it to S3.
- Create Cloud Document for Blacklisted Object - By turning this toggle on a cloud document record will be created for the files that are uploaded on blacklisted objects for easy accessibility.
- Enable Notification - Turn this toggle on to get Email notification of the files that are migrated to Amazon S3.
- Email Recipient List - You can add a list of email addresses that you want to get the file/attachment migration progress notification. Separate emails with a semi-colon.
- Enable Custom Attribute Trigger - Turning this toggle on will send values from Salesforce to Amazon S3 as Custom Metadata. (This can be defined on the Custom Attribute Mapping Additional feature).
- Save File Setting - Once you have configured all the settings according to the use case Save your settings from this button.