To fulfill the use case of creating a mobile application that will be secured by Salesforce Identity using the OAuth 2.0 user-agentflow, where users will authenticate using username and password and not be forced to approve API access or reauthenticate for 3 months, the identity architect should configure two connected app options:

Set Permitted Users to “All users may self-authorize”. Permitted Users is a setting that controls how users can access a connected app. By setting it to “All users may self-authorize”, the identity architect can allow users to access the connected app without requiring administrator approval or API access confirmation.

Set the Refresh Token Policy to expire refresh token after 3 months. Refresh Token Policy is a setting that controls how long a refresh token can be used to obtain a new access token without requiring user authentication. By setting it toexpire refresh token after 3 months, the identity architect can allow users to access the connected app for 3 months without reauthenticating, as long as they use the app at least once every 90 days. References: Connected Apps, OAuth 2.0 User-Agent Flow