The browser extension works on websites of most large journals and we are continuously working on expanding the number of websites we support. To keep up with this fast approach of updating the extension and getting you updates to new site layouts we have implemented a system where we add all approved sites to an "allow" list to shorten the review time we require when introducing new websites to the list. This means that the extension will work only on publisher websites that we specify within our list, as we receive a lot of requests to add more websites to our list and we want to make sure we are able to properly review them so we can ensure support before a website is added to our "allow" list.
Due to this, we have added a function to the extension that allows users to insert a "Save PDF to ReadCube Papers" to websites that have yet to make it to our "allow" list.
If you click on the extension icon on any webpage with an open PDF or use the shortcut keys cmd + shift + s (on Mac) we will try to insert the "Save PDF to ReadCube" blue button in the bottom right corner. This should allow you to get PDFs from any website directly to your Papers library.
You can find our video tutorial below:
For any questions or in case you bump into an issue, you can reach us via email at Papers Support.