How-to play against an A.I opponent? (New PvB feature)

In the game, navigate to QUICK PLAY\BATTLE SCHOOL and then click on CARD BATTLE HELP which will take you to a battle against an A.I opponent to test your true skills.

How to switch the difficulty of the A.I opponent?
-----------------ANSWER:---------------------------
You can change it by using other data.jets found in the Assets folder showing the difficulty level text, so change the name of the default data.jet to like data(mediumdiff).jet will do and rename one of the data.jets with the A.I difficulty name to data.jet (normally). And congrats you'll finally changed the difficulty of the A.I opponent! That's how modding works! ::))

Why is Card Battles Help replaced?
--------------ANSWER:--------------
Because it's obsolescent and it's pretty useless through mods for BTD Battles. We're trying to apply this feature to as many of our mods as possible, such as Brawl Stars Bloons which will get it soon enough for the next update.

NOTE: the default A.I difficulty is Medium when installing the original PvB v14.0.