You can manually mark one of your event dates as Sold Out in three different ways.
First method:
Go to your event and then open the "Event Dates" tab.
Once the list of dates opens, go to the left of the venue name and click the arrow.
From the options that appear, select “Event date settings”.
In the pop-up window, click "Sold Out" and then save.
Second method:
Go to Administration → Event Date Settings (from the left-hand vertical menu).
In the search bar, enter the name of your event, click on the date you want to mark as Sold Out and then click on Choose
In the pop-up window, click "Sold Out" and then save.
Third method:
Click on New Order and from the list of events, find the date you want.
Right-click on it and select Settings.
In the pop-up window, click "Sold Out" and then save.
