"Configure Roles" is eluding me

Anvil Q&A
3

I’m trying to follow these instructions.

First bullet above: I go to assets, and I see nothing anywhere that says “Configure roles…” so I’m stuck right there.

In ‘theme.css’ - I created this:

.anvil-role-qspeer {
  font-size: 13px;
  line-height: 24dp;
}

I go into the properties section of my label control, and I do not see this new role as an option.