Subdomain Redirect to Roundcube

I would like to set a subdomain that points to the Roundcube login page.
Is there a direct URL (doesn’t use “/roundcube”) that can be used for this? GoDaddy doesn’t like anything after the forward slash.

Though this is not possible with the configurations I’ve made, there is an intended path for the desired outcome. By the configurations I’ve made, the “mail” subdomain is for POP, IMAP, and SMTP while the “webmail” subdomain is for webmail. You can find a tutorial for setting that up here:

That is exactly what I needed.
Thank you