The PTO Manager approves the PTO's requested by the users.
The user should be linked with their PTO Managers in the user screen, only then the PTO Managers can see the PTO requested by users and approve them.
To approve the PTO's, go to the PTO tab in Salesforce, and go to the PTO Approvals subtab. You see the PTO's requested by users, select the row by clicking the check box and click the Approve button to Approve or click the Reject button to reject the PTO.
You can also click the + button that is at the end of each PTO row to see the details of the PTOs requested by the users and then approve them. You see the Notes, Out Of Office instructions, Number of days requested in the PTO, etc., when you expand the PTOs by clicking the + button.
By default, the PTO Approvals screen shows the approvals pending for the current month, for all the users for whom you are selected as PTO Manager. To view the PTO of a specific user and specific date, you can select the From and To date, user and click the Apply button and Approve/Reject the PTO's of a specific user on specific dates.