You can choose from a wide array of acceptable file types, including text, image, audio, and video file types, for your submission forms.
1. In the Forms tab of the main navigation bar, click the title of the form you want to update.
2. Open the Form Designer tab.
3. Click the File Upload field at the bottom of your form. (If you don't see an Attached Files field, you can drag one onto your form from the Toolbox on the right.)
4. Select your preferred acceptable file types. You can also specify the number of files submitters can upload for each submission (from 1 to 75).
5. Click the Done button on the right side of the field.
6. Click Save Form.
For more information on creating or editing a submission form, read this article.