For Cloud as well as Server/DC versions of Jira, navigation to ARN screen remains same. Within any given project’s left navigation, you will see the ‘Automated release notes’ link - assuming the app is already installed (see https://amoeboids.atlassian.net/wiki/spaces/ARN/pages/32636941/Installation).
Visibility of the ‘Automated release notes’ menu within a project can be controlled by access/permission settings. Read this - https://amoeboids.atlassian.net/wiki/spaces/ARN/pages/202702910
Jira admins have access to an additional screen for configuring ARN. They have to navigate to Apps → Automated Release Notes → Configurations.
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