Yes, you can use a VPN while trading your funded account - as long as it's not used to conceal or misrepresent your jurisdiction, or to evade any law or regulation covered by your Funded Trader Agreement.
KYC is the exception: you must complete KYC with your VPN off. Using a VPN during KYC will cause it to fail. If that happens, contact our CS team to resubmit your documents without a VPN active.