https://www.worldometers.info/world-population/ukraine-population/
I don’t think this website is completely accurate, but you don’t even provide any source material. Can you back up your claim?
No. I have not conducted a complete census of Ukraine - NOR HAS ANYONE ELSE. And UN, Ukraine and other "expert" information is not backed up by anything either, and moreover, it contradicts itself.
Take claims made by MSM and governments in other specific areas such as refugees into Western Europe, population of Donbas, fertility rates, death rates, and you can immediately see your "this-google-search-told-me-so" information of 43 million is just propaganda / nonsense.
One has to use inductive logic, my FRriend.