In this case, your custom domain will look like
https://schedule.yourbusiness.com
Log in to your DigitalOcean dashboard
Go to Networkings -> Domains
Select your domain from the list
Click on the CNAME section
Fill the HOSTNAME, IS AN ALIAS OF and TTL fields as seen on the custom domain setting page on NeetoRecord.
Click on the Create Record button
For more information, refer to the official documentation