No download button sometimes on PDF viewer

[Lunokhod]

Pale Moon 28.1.0a1 64 bit Linux PDF Viewer 2.0.516 Isaac Schemm
https://github.com/IsaacSchemm/pdf.js-seamonkey
For example, these have no download button:
https://uk.onlinelabels.com/Templates/EU30002-template-pdf.htm
https://www.india.ford.com/brochure/

But these do:
http://www.thechinatravelcompany.co.uk/pages/brochure.php
https://www.toyota.com/brochures/cars-minivan

Many PDF's open when the link is clicked on in the webpage and a download button is shown on the PDF viewer toolbar, but some (perhaps a simpler pdf format, or made available in a different way) have no onscreen download button at the top right of the tab. These ones do not open directly but instead have a dialogue first saying view in Pale Moon or save to file. You might expect you could view it first then choose to save it if it was useful, but the only way to do that is if you either view it then copy the downloaded file from /tmp/mozilla* to another location, or go back and re-download it choosing save from the dialogue this time around. Not a huge issue but a bit inconvenient.