I have dougther she is 4 years old her father left when she was 6 month we don't know where he is he never pay child suppor she have his last name in her birth certificate now I been married for 2 years I have the custody we want she have our last name my husband want adopte her

There are dozens of threads here that ask the same question. A quick review would have answered your question.

Bottomline is you need to hire an attorney to prepare the adoiption paperwork. The attorney will tell you how to show a good faith effort that you tried to find the father. This will all be part of the adoption petition. If you find him and he agrees to relinquish rights or you can't find him but went through the legally proscribed methods to try, then the court should affirm the adoption.