If you are seeing an error message when setting up the QUIC.cloud nameservers for your domain, you can change the assigned servers. Log in to your my.quic.cloud account, navigate to DNS Zones, and select your domain. Then, click the link that says:
If your domain registrar does not accept the assigned nameservers, click here to change nameservers.
This will allow you to assign a different set of nameservers for your domain. Copy the new assigned nameservers and try to configure these with your domain registrar.