Not to my knowledge but you could add some text in the instructions or more direct, see if you can find the label on the url;oad screen and change it there; this would change it across your platform so take notice if this is only for a single course.

Specific File Type For Assignment Uploads;

We've set it up so that students should only be submitting one file, preferably a PNG or JPG, as we requested. But I’ve noticed that some are still sending in DOCX or PDF files, often with way too much information packed in.

To keep things simple and streamlined, we would love to make sure to enforce the rule of only accepting PNG or JPG files for submissions. If there was setting we could use to limit those entries, this would help to avoid the extra load of dealing with large documents and keep everything consistent.