First, pick a viable smart DNS proxy service and then go to the official website of the selected smart DNS proxy service. A lot of Smart DNS proxy services come with trial periods and free tiers. The two most recommended options are SurfShark and ExpressVPN.
Next, find out how the smart DNS proxy works. Different smart DNS proxy services require different methods to be followed. All such information should be present on the official website of the smart DNS proxy in question. Generally though, the user has to sign up for a package on the official website and then find the option DNS Settings. From there, click on something along the lines of a DNS configuration Checker and then click Configure DNS on the current Device. The smart DNS proxy service should open up a new page showing the IP addresses that will need to be used to access proxy servers. After that, go to System preferences and then to network.
From there, click either on Ethernet and/or WiFi depending on how the device is getting internet at that point in time. Then go to Advanced, go to DNS, click the new DNS server button, enter the DNS shown on the official website of the smart DNS proxy service, click OK, and then Apply.
Other smart DNS proxy services have simpler setup procedures. For example, for SurfShark, to get going, users only need to go to the official website, sign up for a package, download the VPN proxy extension for Chrome from the Chrome Web Store, log in and connect to a server located in the US.