I am looking for adapter or converter for 20amp 120 to to 220v 3amp.

Hard to tell what you are doing here, your title and your description are 2 very different things. You can not plug a 30 amp plug into a 20 amp receptacle, the prongs do not match for a very good reason.

And there is NO such thing as the adapter your are asking for.

How would you suppose to make a wire capable of carrying 20 amps to magically carry 30 amps? :confused:

Are you trying to take a European device (or other than the U.S.A.) and use it here

If that is what you want to do, you may check with Radio Shack to see if they have such a converter.