The other way of loading scripts is by using DO SCRIPT. This time the mission editor don't show a file browse button. Instead you see a (very small) text field to enter the code directly into it. It is only useful for very small script snippets. But we can use it to load a file from your hard drive like this:

dofile('C:/MyScripts/hello-world.lua')
dofile('C:\\MyScripts\\hello-world.lua')
dofile([[C:\MyScripts\hello-world.lua]])

Both are shown below. You will require an AI skill S-3B tanker group placed in the mission editor, Set to "Takeoff from Ramp" and ensure "Uncontrolled" is ticked. Ensure "Late activation" is not ticked.

2 S-3B Tankers will be spawned on the USS Stennis as a visible objects (not late activation) but without crew. After 30 seconds, the first S-3B will start up go on station overhead at angels 6 with 274 knots TAS (~250 KIAS). After 1 minute, the second S-3B will start up and go on station overhead at angels 12 with 300 knots TAS (~250 KIAS) Radio frequencies, callsign are set below and overrule the settings of the AI group.

tankerStennis2:Start()

the above is loaded to the Mission editor trigger "Do Script" action after 60 seconds condition. NOTE: Delay to show Aircraft visible on deck then starts later (60 seconds after mission start)..