I have a domain name registered on namecheap. Let's say it is mysite.com. I want this domain to be my personal site. I also want to create a subdomain like myapp.mysite.com for a Rails app on Heroku.
I have tried to configure one in the DNS section of the Namecheap dashboard but I'm new with theses things. I'm using a CNAME type, @ for host and automatic for TTL.
I have also added myapp.mysite.com as a custom domain in my Heroku dashboard.
Am I doing this right? Please explain it in detail so I can lea more about DNS.