That video link was made when Lightroom 3 was current! (before the Book module was in Lr)
I am sure that the Book Module included in Lightroom (all versions since v4) is as capable, or better, that the plugins shown in this video, without having to load or use other software.
Design the complete book in Lightroom and Lr uploads the book to Blurb.
this link is broken. Any updates?! Thank you!
I suspect the 'plugin' has faded from existence.
With respect, I think it might be time to upgrade Lightroom if you are still using version 3.
The Blurb Book module was added to Lightroom v4 in March 2012.
And you have about 1 month to upgrade to version 6.13 (or 6.14) before Adobe ceases support for 'stand-alone' version 6. Or take a Creative Cloud subscription for the Photography plan with Lightroom Classic v7.
If you will not upgrade, you may now only have the option of using other software or the online book design suppliers.