«Are you trying to view a PDF document, but it only gives you the option to download? Don't worry, you can change the Mozilla Firefox browser settings so that you can view PDFs in addition to downloading them. Here's how to do it:

Step 1

To access the Firefox browser settings, go to the top right corner. We will find an icon with three horizontal lines. Click on it and a drop-down will appear in which you must select the option ‘Adjustments’.’.

Step 2

Once inside, make sure that you are in the option ‘General’ in the left column. In the options that appear on the right, look for the option ‘Applications’. Then search for the type of content ‘Portable Document Format (PDF)’ and make sure that in the action column you have configured ‘Open in Firefox’.
From now on you will be able to preview the files directly in your browser without downloading them.