Is there a way to edit Purchase Requisitions/Orders Approval Notifications Page with Page Composer?

Summary

We want to change the label of a checkbox on Purchase Requisitions/Orders Notification Page, but we couldn't access the 'Structure' page on Page Composer

Content

Hello guys!

We are trying to edit the Purchase Requisiton/Order notification page (image below) with Page Composer, but we couldn't access the 'Structure' tab on the approval page.

We'd like to know if there's a way to do it on the approval notification page.

Thanks in advance!

Version

20A