DNS id change possible & steps

The Web is powered by a technology which is known as 'Domain Name System,' ( DNS). It links web servers with their corresponding website domain names. DNS is a very important component in the infrastructure of the internet.
You can follow the following procedure for changing the DNS on your phone.
1. Go to Settings and then go to Wi-Fi. Open the Wi-Fi settings on your device.
2. Open the network options for the Wi-Fi network. Then tap on Modify Network. There might be an arrow on the side.
3. In the network details at the bottom, there will be IP Settings. Click on that. If you don't see the same in your menu there will be an Advanced button. Click on that and then you'll see IP Settings.
4. Change this to static.
5. Change the DNS settings as you want.

Internet Service Provider (ISP) will automatically decides the preferred and alternate DNS server we use. However there are methods to change it.

Change of DNS settings is not possible in the 3G/4G data mobile modes but it can be done in Wi-Fi mode using a router for data.

The procedure to change DNS setting is as under -
1. Click the "Settings" icon on the mobile device.
2. Select "Wi-Fi".
3. Long press the current network, then select the item "Modify network".
4. Tick Mark "Show advanced options" check box.
5. Change "IP settings" to "Static".
6. Add the desired DNS servers IPs to the "DNS 1" and "DNS 2" fields.
7. Press "Save" button, disconnect from the network, and reconnect for changes to take place.

If you would like to change the IP address of the machine, you need to configure a second IP address for the Network and in case, you would like to some specific instructions for the operating system, you may refer to vendors documents. The following steps would be required to change the settings-
1) You need to go to the control panel.
2) Choose the Network by clicking the same and go to the Network Sharing Centre >change adapter settings.
3) Select the connection, which you would like to configure.
4) Select the Network tab.
5) Click the advanced and select the DNS table
6) Click OK
7) Choose the DNS Server address.

The full form of DNS is the "Domain Name System" which mainly works to refer you to the Internet service, it translates a domain name into an IP address. Whereas, every time you use a particular domain name, for some reason, the DNS service translates it to the corresponding IP address. DNS primarily defines an application layer protocol, how application processes running on different systems manage to pass messages to each other. A DNS system has its own network. So if a DNS server can't figure out how to translate a particular domain name, it continues to run from another server, then another server, and so on, until it finds the correct IP address. He keeps on doing the process of sending the request.

You can change the DNS Settings on your mobile:
Open the Settings on the device.
Select the "Wi-Fi" option on your mobile
Select the current network, and then looking for "Modify network", select this option.
You will find another option "Show advanced options" check box, simply click on it.
Now you need to change the "IP settings" to Static
Add the DNS server's IPs.
Then select or Press the Save button.
Finally, switch off the internet or disconnect from the network, and reconnect it.

It seems you are not connected to WIFI. So, changing the DNS in the setting is not possible in this case.

Also, to enter the command you need a bash/ Linux cmd app on your android device. It is highly risky and also most of the commands do not work. All you have to do is, use a VPN.

Please go through the below steps.
1. Open google play store.
2. Search for a VPN like "Secure VPN"
3. Install it on mobile.
4. Open the VPN application.
5. In options, you can choose the desired country as your location. (ex: US)
6. After the successful connection, go to any browser like Chrome and type "What is my IP"
7. You can see the change in your IP address and location.

For mobile phones (in your case OnePlus 7 Pro) DNS or IP setting process is quite different than Desktop or Laptop with or without paid version of VPN services.

Here, you need to download free VPN app from the Google Play Store and follow the steps as per the app instruction is given post download.

Whenever you use free VPN (limited) service with limited country or hour or IP option for internet, your phone automatically change to new (selected country in VPN app) IP address through net usage.

This will solve your issue for DNS / IP in your smartphone than just manual setting steps in phone without required VPN service.