How can I delete an expired CA ?

Hello, I'm facing a problem on UTM 9 (las version). I can't delete a CA from the WebAdmin. The button isn't display, the icon of the CA isn't the same as the others. For exemple, ohters CA look...
Enhancing OT Network Security with a 2.5 DMZ

In our OT network, we're considering adding a Level 2.5 DMZ to bolster security. This would serve as an additional layer of protection between the control systems (Level 2) and the enterprise network ...