how to Delete page(created by app) on app uninstall?

[ll_test]

I have created an app that creates a new page on app install using 

POST /admin/api/2021-01/pages.json

but how do i delete the page on app uninstall?

since when the uninstall webhook get fired after 48 hours  it says access token invalid when  use-

DELETE /admin/api/2021-01/pages/{page_id}.json