If your main domain is pointing properly to the Coaches Console IP address, but the URL with www is not working, then the missing piece is setting up the WWW subdomain (in the account settings of your external custom domain name). You need to add a CNAME for the WWW subdomain that points to the main domain.
Please see the screenshot below that uses an example with a Google domain, follow the steps and just have your domain name written instead of the example "webhostexample.com".
Note: After configuring the WWW subdomain in your custom domain name settings, make sure you paste your custom domain URL as such in your Console Website Settings > "Website Prefix" section > option "I want to use my own custom domain name for my Coaches Console website" > field "Domain URL" (e.g.: www.yourdomain.com).