how do you call in other units when attacking I can only get archers and knights but I would like to use cannon and pyro masters
Before you start a fight you see the enemy tower & units.
At this menu, you can click your own units/spells in the left frame.
Just pick the Archer/Knights and replace them with Cannons/Pyro Masters.
I also recommend unlocking your 3rd unit slot.
seems like you’re a new player , you need to first unlock the other units before you can use them and you do this by upgrading your Troop Academy
If you’re a new player you’ll need to upgrade the Troop Academy to unlock Cannon and Pyromancer
TROOP ACADEMY LEVELS:
click on the image of the unit you want to replace and you’ll see the other units, then just select the one you want =)