What is contributor and how we can do it?

A contributor is a person who contributes. Know your vocabulary

A contributor is someone who has created a giveaway with a gift and has successfully sent it once the giveaway is over. Anyone can "Create a Giveaway" for a game they have access to as either a giftable copy on Steam or a Steam key.

Read the FAQ

Read the FAQs before posting questions like these.

What have you done here the past half year here. FAQ is actually easy to find.

It's 42.

42 is actually wrong, the question was wrong.