If you have not ticked "Static Pages" in your online course, then your customer can mark each page as completed and can also see this in the course menu via the green check mark.
By default, this button is called "Done" for your customer. You can also rename it.
Step-by-step guide
- Go to the settings for the page.
- Provide the label for the button under "Done button text."
In this example we have named it "Complete lesson." This is what it looks like for your customer.