Activation Failed for SR Similarity

Summary:

While following this documentation to activate the SR Similarity Feature:

Documentation:
https://docs.oracle.com/en/cloud/saas/fusion-service/faiec/activate-and-configure-ai-similarity-service.html

Under the AI Apps Administration in Fusion, The Service Request Similarity is enabled, but once we click on Configure and test SR Similarity, Under Configuration, Facing this error:
"An error occurred while activating AI Similarity. Please contact the system administrator and try again later."

I could not find any steps to follow in documentation to resolve this issue.

And just to mention under Insights, there is no data reflected among any of the SR Categorization.

I have attached screenshots under code snippet.