Is this even legal? Employer forcing us to be in a video

Hi, so basically my employer wants all employees to record a video “interview” answering questions about why we like the company, etc. The issue is that the video is going to be posted on social media and I really don’t want my face online.

He said that anyone who doesn’t want to be in the video needs to talk to him, and that we’ll get fired if we refuse.

Is this even legal? Can an employer actually force you to appear in promotional material or threaten termination if you decline? I’m in Alberta.