### Requires Keyboard Maestro 7.1+ ###

--- Set AppleScript Variables to KM Variable Name and Value ---
set myKMVar to "My KM Var Name"
set myASVar to "TBD" -- default value of KM variable, will be updated

tell application "Keyboard Maestro Engine"
  
  ### GET ###
  -- IF KM Variable does NOT exist, the AS Variable will be set to empty string --

  -- Use Explicit Quoted Text --
  set myASVar to getvariable "My KM Var Name"
  -- OR, Use Previously Defined AppleScript Variables --
  set myASVar to getvariable myKMVar
  
  
  
  ### SET ###
  -- IF KM Variable does NOT exist, it will be created --

  -- Use Explicit Quoted Text --
  setvariable "My KM Var Name" to "A new value"
  -- OR, Use Previously Defined AppleScript Variables --
  setvariable myKMVar to myASVar
  
end tell