Could this one also be: "Jag kan inte hitta min plånbok"?
Yes, that is also an accepted translation.
In previous exercises I thought the ownership of the wallet was implied in the swedish phrase, what about this construction requires "min?"
What's the ej? It is to emphasize?
Why "Jag finner inte min plånbok" is not correct?
Hm, I'm surprised that the "inte" can't go at the end of the sentence. I thought in other cases that's possible, or am I misremembering that?