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 temperatureInspection of the gear selector drum
Use a gauge to measure the clearance between fork pin and the slot on the
selector drum.
If the service limit is exceeded, determine which part must be replaced by
comparing these dimensions with those of new
components (sect. 3 - 1.1, Gearbox).
Also check the wear on the drum support pin ...
Riding safety
The points given below are applicable for every day
motorcycle use and shoud be carefully observed for safe and
effective vehicle operation.
A motorcycle does not provide the impact protection of an
automobile, so defensive riding in addition to wearing
protective apparel is extremely importa ...
Warning indication (alarms/signals)
The instrument panel activates in real-time some warnings /
malfunction that are not dangerous for the correct operation
of the vehicle.
At key-on (at the end of the check) one or more "warnings"
are displayed if they are active.
When a "warning" is triggered, the indica ...