The Custom Domain feature in Zoho Assist lets you to access Zoho Assist from the domain of your choice. It enables the organization to customize the URL that their technicians and customers visit to start and join remote sessions respectively.
For instance, if your organization's name is Zylker and your website is "zylker.com", you can access Zoho Assist using "assist.zylker.com" instead of "assist.zoho.com". The Zoho Assist URL can be modified to match your Organization URL in a few following steps.
Steps to Setup Custom domain
4. CNAME mapping and key value parameter are automatically generated in the Verify your ownership section.
5. Copy the key value parameter under the section Points to.

Setup the CNAME in your domain registrar's website:
Open a new tab in your browser and login to your Domain provider account.
Navigate to Domains and then click on the DNS records section.
Click Add to add a new CNAME record.
Choose type as CNAME and enter a name for your further reference.
Under Value section , paste the copied key value generated under Zoho Assist.
Set the TTL as the lowest value or choose 600 seconds from Custom drop box.
Click Add record to update the DNS Record.
Verify your Custom Domain in Zoho Assist Console :
Navigate back to Custom Domain Settings under Zoho Assist Console.
Click Submit and Verify to begin SSL Certificate installation.
New SSL Certificate will automatically be installed usually in 3-5 business days.
16. Once installed, Custom Domain will be active and the settings page will be updated with the custom domain details.
To enable / disable the existing Custom Domain
Go to Settings > Rebranding > Custom Domain.
In Custom Domain, click on toggle icon to enable or disable the mapped domain.

Note : Once custom domain is enabled, customers can join the session either through your organization's unique custom join URL or by visiting join.zoho.com.
To ensure customers can only join through your organization's custom join URL or via customer plugin, enable the "Allow customers to join a session only via the organization's custom join URL" checkbox under Domain settings as shown below. Once enabled, customers can only join the session using the unique session key provided by your organization. Session key from other organizations will not allow customer to join the session. Customers cannot join from join.zoho.com or from any other generic domain join URL.
To delete the existing Custom Domain
In Custom Domain, click on
to delete the mapped domain. Click Delete in the confirmation prompt as shown below.