The only filtering that Firefox is directly involved with are those you see under Tools > Options > Security for phishing and attack sites. Amazon.com is not one of those.

Most likely the type of filter involved is one of the many parental controls extensions (see last link for links to several of them). You should be able to get the information you need from the extension once you identify the extension involved.

Did you mean FoxFilter addon? Click the "firefox button "on top left, go to "addons" and find the FoxFilter addon. Next click the "disable" button (if you're not sure or want to use it later) or "delete" button (to delete it from the browser). You can then enable it or install again if you like.

Thanks this helped I had put on fox filter on as my grandchildren had been using my laptoop. Have disabled it for the time being. Able to print out my order. Many thanks once again