Feature Request: Hang up function key

[videomike]

Very often when you call hotlines or call centers, the people there have computer phones also and don't hang up the phone but wait for a you to hang up. I sometimes have a lot of open windows and it takes some time for me to find the telephone window and hang up the call. This leads to some awkward situations sometimes... My Mac has function keys from F1 to F19, would it be possible to assign a Function key in the settings to hang up the phone, e.g. it will hang up when I press F19? kind regards

Michael