At this time, Classwork.com does not automatically detect fillable form fields in a PDF or generate interactive fields for you.

If your PDF already contains form fields (from another program), those fields will not be recognized or converted when the file is imported into Classwork.com.

To make a PDF interactive, you will need to manually add Question Types or text fields using the Classwork.com editor, placing them where students should respond on the page.

This also gives you the option to use the Question Type of your choice — making your Activity more interactive and ensuring it can be autograded when possible.