Hello @francis_ha ...
In any given assignment within your course, you can restrict the type of files that can be submitted to you. For example, if you only want students to submit a file to you with a *.jpg file extension, you can do that. Please check out the information on this Guide: How do I create an online assignment?. Check out the section on "Restrict File Types" about 3/4 the way down the page. In the box to specify acceptable file extensions, type in something like jpg.
I hope this helps, Francis. Let Community members know if you have any other questions...thanks!
