Announced in March, Microsoft To Do has been integrated into the Outlook Mobile app as an additional app. To Do is now listed as an app in Outlook and can be reorganized if required.
Language of the Outlook Mobile app
Outlook Mobile must be used in English for To Do in Outlook. The To Do app is not visible in any other language.
To Do opens directly in the Outlook app. The To Do Mobile app does not need to be installed.
Like in To Do on the web, the To Do integration includes an overview of the current tasks for the day, important tasks, planned tasks, tasks assigned to me, and marked emails (if enabled in the settings). Further user-defined task lists are also available.
Administrators can configure a policy via Intune to hide all Outlook apps. The documentation describes com.microsoft.office.officemobile.TeamsApps.IsAllowed.

Hello – The TO DO app is not showing in my OUTLOOK mobile app. How do I get it as a part of MS Outlook mobile app??
Hello Narain, is the To Do app available in Microsoft 365, or maybe the service plan/license is inactive for your account? Also, is To Do available in Outlook on the web?