In the Ultima 9 directory there is a file called default.kmp. When opened in a standard wordpad or other text editor you will find the following text line:

[Cheat Commands]

Simply add the following lines underneath it:

alt+shift+i = toggle_avatar_invulnerable
alt+shift+l = toggle_avatar_fly

During game play the corresponding keys (alt+shift+i & alt+shift+l) will activate the cheat functions.

You may also bind the following codes just as you did the ones above:

pass_one_hour
unpass_one_hour
sunrise_sunset
pass_one_minute
unpass_one_minute
toggle_sun
toggle_wind
toggle_storms
toggle_avatar_fast