During installation of Bot History Viewer, you will need to activate it.
How to activate the App the first time?
During installation Zendesk will prompt you to enter an App ID and encoded token.
The App ID is something you request via the Admin Center > Apps and integrations > Conversations API. You can find more info in this article
The App ID can be copied over directly in the Apps settings
The Key ID and Secret key are needed to create an encoded token.
Ensure you copy them before closing the new API Key