Please create the document which is required for duty-free procedure.
Could you please fill in the document which is necessary to do duty-free procedure.
create a document : 書類を作成する
duty-free procedure : 免税手続き
fill in : うめる
Could you please ~ : ~していただいてもいいですか
Could you please = Would you please
Could you をつけるとより丁寧な表現になります!