You can customise the filename for the single form PDF downloads via the template editor downloads settings section.
Once you click on the 'Edit PDF Filename' button in the 'Custom Filenames in PDF Downloads' section you will be able to edit the filename in the 'Edit filename' modal.
You can add/remove values in the filename structure as well as reconfigure the ordering of the values added. Once you have configured the desired filename, you can save your changes and the new filename should be updated in the template settings preview above.
Filename Settings
The Filename Settings section allows you to further customise your filenames, by setting a specific format beyond the fields selected to appear in the filename.
Filename Breaker: You can customise the filename separators - the default option will be hyphens ("-"), with an option for underscores ("_") as well
Filename Case: You can select how the text in your custom filename will appear
On a final note, this is only available for single file downloads via the form modal. This feature is not available for register view in the Home/Team folders