I can't update my macbook pro what is the issue!!! 13" early 2015 model

This seems relevant to your issue: https://discussions.apple.com/thread/253373860

"If you find your mac can upgrade to the newer OS's like macOS Mojave 10.14, macOS Catalina 10.15, 

macOs Big Sur 11.6 or the latest macOS Monterey 12.0 I would recommend you upgrade to 

macOS High Sierra 10.13 first."

fahadfromquincy wrote:

How can I update it?

Update to what...?

does your Mac have a third party SSD ?

One known issue Failed to Install Monterey — a non OEM Apple NVMe / PCIe SSD

The work around is to reinstall the OEM Apple Drive upgrade that drive which will flash the board, then reinstall your third party drive and now you can run the installer on your machine.

The EFI /Firmware part of the Monterey pkg is verifying for OEM Apple Drives and fails to upgrade. The EFI boot ROM is required to Flash the board and is required to successfully install Monterey.