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/39720579-0f1e-457a-924d-1f3d07301591/BC-PNP-Skills-Immigration-and-Express-Entry-BC-Technical-Guide.aspx