No, the cable that came with your phone should work :)
To debrand, you will need to download a Main and FS from here, and then flash it with XS++ (PhoneXS).
You will also need the Flash Driver for XS++ to work.
Note: XS++ will not work with non-CID49 DB2020 phones!
Check you CID with XS++ before proceeding!!
If you have a CID49 phone, download a CID49 firmware from here, and not any CID51/52 firmware!