External USB Encryption

I have an external 3TB seagate drive connected to my My Cloud EX2 Ultra, the drive is used for backups and formatted to NTFS. Is it possible to have external backup drives encrypted? (This is for theft protection etc).

I have checked the manual but can’t find anything regarding this.

Not a good idea to encrypt external hard disks. Use a DVD/BR and password encrypted 7z files which are recoverable easily while the hard disk is vulnerable.