How to use Firewall and other spells beyond the first four?

[Twistor]

I don't see a menu, from which to choose them, nor have I found a keyboard shortcut for them. How can I use them?

[Twistor]

Aaand I have discovered the answer to my own question. In the Store for Spells, you have to click the grey, empty circle next to the spell you want to use, and then you can add it to your loadout to replace one of the other four spells.