When variables are not found this usually means you haven’t specified the variables in Google Tag Manager. If you have data layers set up on your complete page, you can look at those, and then specify these in Google Tag Manager.
First, you have to make sure that you have set up a data layer containing the essential information we need for Divvit to work correctly. Find the exact data layer variables and a step-by-step guide over here.
Here is how you can set up new data layer variables for Google Tag Manager:
You might also find this article useful if you are setting up with Google Tag Manager: Triggers to use in Google Tag Manager