I think Close Procurement vs Close Project is one of the most misleading concept in PMP Exam.
According to the PMBOK Guide
“Close procurement is the process of completing each procurement.
"Close project or phase is the process of finalizing all activities across all of the project management process groups to formally complete the project or phase.”
The definition clearly tells you that the close project or close phase is performed when the project or phase is finally completed and deliverables are accepted. The close procurement process must happen before the close project or close phase process.
There is a good resource which explains the difference between
close procurement and close project