Understand that if you use the vehicle primarily in EV mode, the Internal Combustion Engine (ICE) is rarely engaged. If you go "too long" without starting the ICE, the Clarity PHEV will go into a maintenance mode, and start the engine itself, to keep things nice and lubed. However, there's also the issue of calendar life. Several of us here have adopted the habit of simply changing the oil yearly, even if the ICE mileage is less than the "rule-of-thumb" 3,000 miles. The issue is that there's not an "easy" way to know what your ICE odo miles are.
With the above in mind, not changing the Clarity's oil for two years probably isn't as big a deal as you might think.
Some of us here have installed an aftermarket engine hour meter, just to give us a little more data on ICE use. They can be had for less than $15, and installation is relatively easy, if you don't mind wrenching on an engine. I removed the far right spark plug connector, and wrapped the requisite wire around it. There's a video linked on these fora that shows it being done on a Clarity PHEV. If I come across it, I'll add the link here.
This is the one I got, and it seems to be working just fine:

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