Approvals in Microsoft Teams is a way to streamline all of your requests and processes with your team or partners.
https://support.microsoft.com/en-us/office/what-is-approvals-a9a01c95-e0bf-4d20-9ada-f7be3fc283d3
The Approvals app is available as a personal app for all Microsoft Teams users. The Approvals app provides a simple way to bring auditing, compliance, accountability, and workflows to both structured and unstructured Approvals in Teams.
https://learn.microsoft.com/en-us/microsoftteams/approval-admin