Try the JQL as below for your Kanban board filter. This will pull all the tickets from your project which are not marked as completed yet or the ones marked as completed in last 90 days.
project = "Project Name" and (resolution is EMPTY OR resolved >= -90d)
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events