Create a backup policy on the NSX Manager

1. Login to the user interface of NSX-T Manager.

2. On the main navigation bar, click System. Select Backup & Restore from the navigation pane.

3. Click Edit:

Enter the IP or host name of the backup file server in the IP/Host name text box.
Change the default port if required.
Enter the user name in the User Name text box.
Enter the password in the Password text box.
Enter the absolute backup directory path in the Destination Directory text box. The directory must already exist.
(Optional) Enter a Backup Encryption Passphrase to encrypt the backups. You will need this passphrase to restore a backup. If you forget the passphrase, you cannot restore any backups.
Enter the SSH Fingerprint of the server that stores the backups. You can leave this blank and accept or reject the fingerprint provided by the server.
Click the Schedule
Enable Automatic Backup.
Define the backup Frequency.
Set the Detect NSX configuration change toggle to Enabled to trigger a backup when the configuration of the network changes. Configure the interval.
Click Save.