Need advise - Proof of valid Job offer

[_696_]

Hello there, I finaly got an employer willing to provide me with a job offer for CSQ [Quebec Skilled]. Now the thing is, I´m not sure whether just a letter from this person stating he would provide me with a position in the company once I land would suffice, I'm guessing that we're probably missing something in here. So basivally, what should I ask this person to do / send and to whom?

Thanks.