Garmin Fenix - can it be done?

So I'm going to start by stating that a) I'm not a training fanatic and b) I know the data outputs can be vague/inaccurate c) none of this really matters as bikes are brilliant whether you have data on how brilliant or not.

However, I do find some of the stuff like VO2 Max, resting heartrate, sleep score etc. quite interesting and work on the basis that even if it isn't accurate, the bit that should be more "reliable" is the change in readings for me as I'm the consistent source and I do like to see how I'm changing (getting worse mostly).  I'm also trying to shed a bit of timber and get a bit fitter so these measures are superficially useful and a bit of a psychological boost when they go in the right direction.

Until now my Fenix 6 has only shown VO2 Max for running as that's the only time it can measure enough parameters for the relevant exercise.  However, I've recently bought an e-bike and the watch can connect to the cadence and power meters (records power 'in' from me as well as power 'out' from motor) so is now showing a VO2 Max reading for cycling as well.  I'm rubbish at running and so was pleased that my watch agreed that I performed better at cycling and gave me a bigger VO2 number.

So, to the question, can I get similar data from my analogue bike without buying power meter cranks/pedals on the basis that they're really expensive, it actually doesn't matter that much and I'm curious rather than serious.  I also run flats so its clearly not about outright performance its just about measuring me and the changes in me.  I've seen you can get a Garmin bundle of speed and cadence sensors that can be switched between bikes so would this provide enough data to give a bit more insight?

Thanks.