Thanks for posting your question in the Microsoft Q&A forum.
Depending on the Planner license you have, you can have various features to work with:
https://www.microsoft.com/en-ca/microsoft-365/project/microsoft-project-licensing
https://www.microsoft.com/en-us/microsoft-365/project/compare-microsoft-project-management-software
But Microsoft 365 and Office 365 users with E3 and E5 licenses are limited to mark a task as complete or update the task progress or “% complete” of a task assigned to them in any project they have permission to.
[https://learn.microsoft.com/en-us/project-for-the-web/office-365-user-view-access-to-project-and-roadmap
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