Google Analytics has recently updated and defaulted their platform to Google Analytics 4, which provides a new way to measure all sorts of conversion and custom metrics.
For some tools, a UA property is still required to be able to plug into the system. To create a combined G4/UA tracking, follow these steps:
Go into your analytics account and click the "Create Property" button:
Name your property and then click "Show advanced options":
Click the "Create a Universal Analytics Property" to on, put your URL in, and make sure the top radio button is selected. Click "Next," answer a few questions about your business, and then click "Create.
Once set up, make sure you are on the correct property, click Data Streams, and then click on your property:
Click the "Global Site Tag" option, copy the code, and place it into the header of your site:
Once that is in you will be able to stream in data through G4 and through your UA tag.