You can create and add an HTML document to your content by following these steps:

1. Go to Content in your course.
2. Click on the Unit where you want to add the HTML document.
3. Click on Create New.
4. On the next screen, select Page.

1. Enter the title of the document.
2. If you want the document to be temporarily available, enter a date here; otherwise, leave it blank.
3. You can use the various features of the text editor tool.
4. There are different templates available that you can select.
5. Here, you can specify the period during which you want the document to be available.
6. It is possible to add Release Conditions if you want students to complete something before they can view this document.

When you're done, click on Save and Close at the bottom. Don't forget to click the slider next to Hidden so that the document is visible to students. It will then show as Visible.