Project Management Template: How do I create Strikethrough for events that are already completed?

I am using the Project Management template.
I can’t find how to implement the Strikethrough feature for an event that has been completed like is shown on the website.

I asked on the FB group and was told there is a checkbox, but that seemed to be for the Fiction template. I have been unable to find it so far on this template.
Thanks.

The strike through feature can be set for properties of the type Checkbox or Percentage. If the property is checked, or set to 100 percent, then the event is struck through.
This hasn’t been set for any properties in the default Project Management template, which is why you couldn’t find it. We realise however that this is something that would be helpful to have there, as so will look at updating it, and potentially changing it so that list type properties have this ability as well (for example the Status property in the template would strike through an event when set to “Complete”)
In the meantime, you can add your own properties that have this feature. If you open Settings (the cog icon), then click the Data Types tab, then Edit, you will open Advanced Settings.
Click on Properties, and click on the Add button at the bottom of the list to add a new one.
Name the property, and choose either Yes/No or Percentage from the dropdown. Tick the box “Indicate item completion” and select which Item Types you want it to belong to (eg. Task). Then click OK. Now your timeline will have this property with this feature.