Yes, It is a must. It is on page 60 in the below link. And you don't need your CEO to write it for you. You can ask yours supervisor or your mentor.Is recommendation letter a Must ? They asked my employer via email for it in 1 week, but the Ceo is quite busy and could have missed it.
https://www.welcomebc.ca/getmedia/3...ion-and-Express-Entry-BC-Technical-Guide.aspx