This is a Premium feature of Cowlendar. You need to upgrade your plan if you want to use this feature and you are a free user of Cowlendar.
You can hide "free slots count" by going to Apps > Cowlendar > Settings > General Settings > Untoggle "Show free slots count"
In your Shopify admin dashboard look at the left panel and click on Apps.
Click on Cowlendar.
Click on Settings and into General settings.
Scroll down a bit and find Show free slots count.
Unselect this option.
Last updated 1 year ago