After successfully login to you hostgator server account, click on "Manage Orders" and the click on "List/Search Orders". screenshot of this page is given below

In list/seach order page, you will find your primary website domain name and corresponding server package. Click on your primary domain name as show below with screenshot

Then click on manage web hosting title where manage of FTP account, file manager, databases, backup etc is written

After opening cpanel, scroll down to find "domains" category panel. On this panel, click on "Zone Editor". Screenshot of his page is show below

In Zone Editor page, you will find all your websites domains. Click on "Manage" corresponding to that website which TXT recoder you want to add.

Now, click on "Add Record" and then select type as "txt". Then paste your TXT record text that you have from Google Search Consile to record column and type the domain name on name column. Then click on "add record" button and done