It is possible to control calls using R/ Flash button on W02FXS 2018, W04FXS 2017 and W24FXS 2015-2017.
Permalink: https://confluence.wildix.com/x/kQmIAQ
Control second incoming call during an active call
In case of the second incoming call during an active call:
- press R to put the active call on hold and to answer the second incoming call
- press R+1 to end the active call and to answer the second incoming call
Control one active call and one call on hold
In case you have one active call and one call on hold:
- press R to swap the calls (or R+2)
- press R+1 to end the active call and to resume the call on hold