Nope. If you want to convert a SIM card (micro, nano or whatever size, they're all the same thing just differently cut plastic part) to eSIM you're SOL. Unless maybe if you have a very ancient SIM card that you've refused to upgrade (but then you're probably without LTE).

The reverse might be theoretically possible during activation (if you feed the QR code to your own custom device and your software implementation doesn't guard the keys, letting you copy those freely), but I suspect there is some form of attestation so it won't let you activate with anything but "trusted" devices (by network, not yourself). And if eSIM is already activated on a phone, you most likely won't be able to extract the keys, because those are most likely protected with some sort of secure element.