Lorna, the links in the ebook are complete and valid links whether you click on them or copy them into your browser.
So, if you click on them they normally go directly to that lesson. If for some reason your browser is not doing that just copy the link and paste it into your address bar on your browser.
Please try that and let me know if any links are still not opening. Also, be specific with what you are using (ipad, computer etc) and if it’s every link or which one.