Certificate to be used for Basic Station with TTNv2

Hello, I searched for what certificate to be used for Basic Sattion on TTNv2.
I found:

  • isrgrootx1.pem (like for TTNv3) => but I did not success connect on server wss://lns.eu.thethings.network:443
  • trustid-x3-root.pem => This one is working correctly but the expiration date is now in less than 20 days (March 16th)

What certificate can be used with a longer time duration on TTNv2 ?