Wow. What kind of bullshit ISP blocks outbound DNS requests? I would bitch loudly at them as they have no valid excuse for doing that. Anyway… In that case you have a few options. You can use DNS over https but that’s supported primarily by browsers. Not so much other desktop applications. I would get a router that’s capable of WireGuard and connect it to ProtonVPN (or another VPN service of your choice). You don’t have to route all traffic over VPN if you don’t want to but at least you’ll be able to use whatever DNS server you want.