The activation of this (amber yellow) "warning" indicates that the hands free system has detected that the battery that permits the active key (1, fig. 62) To communicate and turn the vehicle on is almost discharged.
Note
In this case, ducati recommends replacing the battery as soon as possible as described in the paragraph "replacing the active key battery" (page 88).

Hands free key (hf) not recognised
High engine coolant temperatureHow to use this manual
How to use this manual
This manual has been prepared for technical personnel at ducati authorized
service centres with the aim of providing
fundamental information on how to work in accordance with the modern concepts of
"best practice" and "safety in the
workplace" during the maintenance, re ...
Reassembling the front footrest brackets
To reassemble the brackets (6) and (21) carry out the removal procedure in
the reverse order; tighten the screws (7) to a
torque of 25 nm +/- 10% (sect. 3 - 3, Frame torque settings).
...
Refitting the clutch master cylinder assembly
Insert the clutch master cylinder assembly (3) and the clamp (6) on the left
handlebar, so that the top mating faces
match the mark (z) on the handlebar as shown.
Couple terminal (6) to the clutch master cylinder control and fix them with
the screws (v).
Tighten the retaining screws ...