Furuno FELCOM 81B - Manual (Page 59)

5.5 Facsimile PFX-50 Setting
Turn on the power while dialing [*], [1], [3] to initialize
the PFX-50's memory. Change the dial mode to "push
button" with the MODE switch. (Choose position "T". )
5.5 Facsimile PFX-50 Setting
5-5
Dial Mode
MODE Switch
Chosse "T".