1. If you are remoting to a PC using CITRIX (or anything else) as it is
    stated in the question.  
    
    In "Start Menu" of the WIN10/11 one can search for "On Screen
    Keyboard" and launch the on screen keyboard. Then simply set the
    state of INSERT key there.

 2. In addition - if one is using the full size Apple keyboard ( with
    num keypad ) on WIN machine or runing a virtual WIN machine on MAC
    OS X 
    
    Switching numeric keypad off ( using "**clear**" button ) and then
    pressing "**0**" key. It does togle the state of the INSERT "key".