Since all browsers allow users to view the source code of the website, this means that anyone can see your live chat code. Some spammers may even copy the code and paste it on other websites in order to send a lot of invalid messages to your chat window and harass your customer service personnel with irrelevant questions.
With the Trusted Domain feature, you can create a list of domains that you know and trust. Only these domains are allowed to integrate your chat tool. If someone tries to add your chat code to any site outside the trusted list, the chat code simply won't work on those sites.
How to add a trusted domain
As an administrator, you can add trusted domains at any time. Your chat code will only be enabled in these trusted domains.
Go to Settings → Installation → Trust Domain and click the Add button

Enter the domain information in the pop-up window and click the Save button

To add multiple domains, repeat the steps above. Your chat code is now protected and will only work on domains you trust.
Make sure to update the list when you install the chat code on the website you want, because the code can only be used on your trusted domain.
How to delete a trusted domain
If you need to delete a trusted domain, just hover over the domain and click Delete

How to use trusted domains
Trusting a domain establishes a trust relationship between the domain and its subdomains.
Trust Primary Domain
If your site has multiple subdomains, you can trust all subdomains at once by simply adding the primary domain to the list of trusted domains.
This is especially useful if your site is available in multiple languages, such as the English version for en.example.com, the Japanese version for jp.example.com, and the French version for fr.example.com. You don't need to add each subdomain to the trusted list one by one,Simply trust the core domain example.com, and all language subdomains under it are automatically trusted as well.
Trust only subdomains
On the other hand, if you trust only one subdomain, the trust does not extend to its primary domain or to other subdomains under that primary domain.
For example, if you trust only the English subdomain en.domain.com, the primary domain domain.com will not be trusted, nor will fr.domain.com (the French subdomain) and jp.domain.com (the Japanese subdomain). HoweverWhen en.domain.com is added to the trusted list, all higher-level subdomains under that subdomain (such as blog.en.domain.com, sales.en.domain.com, and so on) are automatically trusted.