AirPod pairing with Panasonic Phones

I just purchased a brand new Panasonic phone for use with my VoiP service (see, I'm not that antediluvian). There are still reasons to have a home phone for me, mostly to do with international calling and the fact that cell service in my neighborhood is lousy.

Try as I might to get ANY generation of AirPods to pair with my Panasonic phone (knowing that there is no PIN for AirPods, so it shouldn't matter what you enter) the phone just will now recognize the AirPods.

Contacting Panasonic support was a disappointment: they are stating that all of their phones use BT 4.0 or BT 4.2, and that Apple uses BT 5.0 or later. They do not offer any kind of software or firmware upgrades for any of their products, and they suggest using the Cellular function and pairing the AirPods to my iPhone. This doesn't make a whole lot of sense to me, if I am paired to my iPhone I'm going to use that to do my calling and not my Panasonic home phone.

Any thoughts or ideas on what can be done to make them usable besides finding another brand of home phone to use? Pity they are a full generation behind the standard, but perhaps there is another way to get it to pair?