I just happen to have a 2647A User's manual
and a 2647A Reference Manual [no terminal].
User manual, CH. 6, starts:
This section describes briefly how to load
the BASIC interpreter from your BASIC
Multiplot cartridge tape (part no. 02647-13301).
Sounds like you need a tape.
Keven Miller
kevenm(a)reeltapetransfer.com