The subdomain feature only works with CloudFlare, to proceed please follow the insturctions below:

1) Head to Admin area CF -> Billing -> Domain -> API Settings -> Create New

2) Account Email: Your CloudFlare Email Address

3) Domain: The domain you want to use, such as example.com don't include https

4) Zone ID: Cloudflare Dashboard -> Select Domain -> Zone ID (Located Bottom Right)

5) Global API Key: Can be found here: https://dash.cloudflare.com/profile/api-tokens

6) Send us the details above by creating a Discord Support Ticket here: https://dc.mcst.io

7) You're good to go! Kindly wait for support to attend to your ticket once submitted.

Don't own your own Domain?

Not a problem!

Please see: https://dash.mc-servers.tech/page/wiki for the MCST-Hosted list of domains you may use for Free. 

Navigate to your Dashboard "My Plans" -> "Settings" -> "Subdomains" , and select your free MCST-Server sub-domain.