How can i set WILDCARD subdomain for my site

[rakin]

HI SIR/MAM recently i have installed VESTACP.and i am very pleased to install VESTACP.i want to give the opportunity to the users to create subdomains.but i want to set WILDCARD SUBDOMAIN.so that users can create their subdomains and it can be visited automatically without adding any dns record.how can i set UP WILDCARD SUBDOMAIN DNS.

[ScIT]

wildcard dns record: *.yourdomain.tld