Burndown chart no longer available on free tier?

Hi everybody

I have a project hosted on gitlab using the free tier. I remember that a couple of months ago I could see the burndown charts according to the status of the issues on my milestone. Now this option seems to be unavailable.
I just wanted to confirm if this feature have been moved to the Bronze tier, or there’s some way to access it from a free account.
I also wanted to know which is the tier corresponding to the on-premise (the open source) version, just to be sure what feature will be available if I deploy gitlab on my own server.