Basically you could see from the below steps:
1. Go to Office 365.
2. Go to Admin Center.
3. Go to Dynamics 365 Administration Center.
4. Click on Instances Tab.
5. Select on target instance.
6. Click on Solutions from action panel (new tab will be opened).
7. Ensure Customer Service Hub is installed.
You can see it from Dynamics->Settings->My apps
-Also Usage of Parature knowledgebase as the knowledge management solution is deprecated. This feature is replaced by Knowledge Management features in Dynamics 365 Customer Service.
docs.microsoft.com/.../important-changes-coming
Error message you receive is from the learning path authors generally If you're not a member of the Office 365 Learning Path Authors security group,
Add a user
Go to the admin portal for your Office 365 tenant by selecting the Navigate to other applications button in the upper-left corner of the page when you're signed in to Dynamics 365, and then select Admin.
You might be asked to reenter your password.
In the Admin center, select Groups.
On the Groups page, select the Learning Path Authors security group.
In the Members row, select Edit to add users to the group.
Select + Add members, and then specify or search for the user(s) you want to add to the group.
Select Save when you're finished adding users.
Note
Another way to assign the group to a user account is by selecting Users > Active Users, selecting the user you want to add, and then selecting Edit next to Group memberships to select the group(s) to add the user to.
