Software such as Octoplus or other professional service boxes are used to write the dump data back to the device.
Due to copyright and security concerns, I cannot link directly to files. However, reliable sources include: cam-l21 dump file
A full dump file typically contains several key components required to restore the device to a functional state: Software such as Octoplus or other professional service
Resolving situations where the phone is stuck on the Huawei logo and cannot be fixed by a simple factory reset or standard firmware update. cam-l21 dump file