Make an icon for a behaviour appear after upgrade?

[Kabel]

I have added a behaviour to a unit and I´ve made an upgrade for it. The behaviour starts to work when the upgrade is researched. Everything works fine.

I use an icon on the unit to show what the behaviour does. I want it to be dark when the upgrade is not researched plus that it shall say "- requires upgrade X".
Like on a normal ability button for a unit.

How do I do this?

 

[Dr Super Good]

Use a requirement. The use section must be set so that it is only enabled when the passive should be used.

You then add this requirement to the behaviour.

You can also add it directly to the unit's command card passive button but I am not sure if this will disable the behaviour's effect.

 

[Kabel]

I added it as a requirment to the command button. It works fine now. Thanks!