We bought the BinaxNOW Covid-19 Ag test kits online (that is the very specific name for the telehealth version of the Binax test) made by Abbott Labs. When you purchase the kits, the price includes the online test fee; it's built into the cost, so you won't have to pay again.
An affiliated company/service called eMed does the test supervision. Before you take the test, download the Navica app on your smartphone and register. That is where your test result will be sent. When you are ready to take the test, log in on your laptop, iPad, or cell phone to start.emed.com. It's an internet connection, not a phone call. The connection will use the camera on your device. Hint: a laptop is easier because it can be angled to show the table in front of you as you take the test and it has to stay focused on your test for 15 minutes. It is harder to do with an iPad or phone, but not impossible.
You will be connected to a test administrator over the internet; you will hear the administrator but not see them. They will see you, however. They walk you through the test, including watching you open the test kit, so you must make sure it remains sealed until you start the online session. You will take the test and they will verify that you did it correctly. When you have placed the drops in the cartridge, the administrator will start a 15 minute timer and then they will sign off. However, you must keep your camera focused on the test cartridge the entire time so they know you have not switched it out. After 15 minutes, another administrator comes on and asks you to hold the cartridge up to the camera so they can see the result. They will verify if the test is positive or negative. Once that is determined, eMed will send an email to you with your results, as well as sending a QR code to your Navica app.
It may sound complicated, but it is in fact super easy (with a laptop.) We have used the tests twice, once at home before departing on a cruise, and once in our hotel in Rome before returning home. It worked flawlessly.
Hope this helps. Happy to answer any questions.