Setting Up a Subdomain with a Custom Domain on a Vercel-Deployed Site

Vercel Configuration

Go to the domain settings page from Settings → Domains in the admin panel, and enter the subdomain you want to set in the domain input field.

Here, you set the CNAME displayed in the domain management service you are using.

Domain Management Service Configuration

Taking Onamae.com as an example.

Go to the DNS record settings page from Use DNS Record Settings.

Enter the CNAME settings displayed on the Vercel side.

After completing the settings and waiting for several minutes, the settings will be reflected, and you will be able to access the site using the domain you set.