500 Internal server error - when requesting notify change with none existing policy

Description

When subscribing with webhook for changes for none existing policy the response status code is 500 Internal server error.

Request

curl --location 'https://vault.vereign.com/tsa/policy/policy/policies/example/nonExisting/1.0/notifychange' \
--header 'Content-Type: application/json' \
--data '{
  "subscriber": "bace",
  "webhook_url": "https://webhook.site/4d79f1a0-9608-4d5b-9187-dfe18ae3467b"
}'

Expected

404 Not Found

Actual

500 Internal server error