Decks or phases in the library may have different content as a requirement. Unlock requirements may include assessments.
Note: A deck must be linked in the library in order to include requirements for activation.(How do I add a deck to a topic?)

To add an assessment as a requirement, edit the desired phase or deck. In this article, we explain the process using a phase in a learning path.
In the phase editor, you will find the item Unlock Requirements at the bottom. Click on Add field to add a new requirement. A drop-down field appears, which you can use to add a learning content from the library as a requirement. Click in the dropdown field and a list of content from the library will appear. Tap in the field to search for specific content. Assessments are also labelled as such in the list.

If you have selected an assessment as a requirement, the unlock type Passed is automatically selected. The selected exam must therefore be passed in order to unlock the learning content.
Proceed in the same way if you want to activate one or more decks by checking them.
You can find out how to add requirements to decks in the article How do I add an activation requirement to a deck?