1. Open the bookmarks / favorites sidebar, which you can open with a button at the top left of the window, or by selecting "View -> Show Bookmarks Sidebar" from the menu.
2. Drag this Readlang Web Reader link into the Bookmarks Sidebar.
3. Visit a webpage you'd like to read in the language you're learning.
4. Click the "Readlang Web Reader" bookmark that you just created.
5. The Readlang toolbar will now open, and you can click on words or phrases within the web-page to translate them.