Unable to configure Wireguard client

I try to use my Vyos as a client to Wireguard. I got the configuration from the VPN service. I got stuck at DNS. I could not find a way to configure the DNS the client was expected to use. Is there impossible to have a DNS address in the configuration or am I doing something wrong?

You have to use IP address

I tried "set interfaces wireguard------dns-address 10.xx.xx. " I tried name-server 10.xx.xx. and lots of variants. I do not think an IP-address is enough. You have to tell what the IP-address is. “set interfaces wireguard wgxx peer name server address 10.xx.xx” or so. The problem is that DNS, name server is invalid.

set system name-server x.x.x.x

Does wireguard connection use a hostname or IP address to connect the vpn to?
If this is a hostname, setting system DNS to wireguard DNS server might lead to chicken and egg situation.