A wall oven with a regular power cord, is it normal?
I think everyone commenting on this question agrees it is not the correct cable. I am assuming that what you call a label is actually the nameplate rating of the oven. The 120/240V rating means it operates on both voltages. 240V requires to phase conductors A &amp; B and the 120V operates on a single phase and a neutral, and the you have to include a grounding conductor. So that would be 4 conductors two would be any color usually black and red, and one white for neutral and one either bare or green for ground. 3.8Kw means it needs at least 15.8A to operate or a 20A Breaker. 

You don't state whether you are installing this oven at a new location or replacing it so I am assuming it is a new installation. If that is the case you will need a NEMA 14-20P for the cord cap and a 14-20R for the receptacle. You need to feed the oven from a 20A 2 pole breaker with minimum #12 conductors. If you are using NM the it would be a 12/3 cable with a ground.

For the record, I would never recommend to buy this type of appliance from ebay. Don't be surprised if you did all of this work and it doesn't work. You might take this to someone and have it tested before installing it.

Hope this helps and good luck.