To add attachments for case module, go to the detail view of a record or if you want to relate attachment to logged in contact, then navigate to attachments from the module list
Upload the file for attachment by clicking on the ‘Choose File’ button, you can also enter the description for the attachment in the ‘Description’ text field.
Now click on the ‘Upload’ button to upload the attachment along with its description.
You can also preview the uploaded attachments either from a detail view or list view.