Install linux-headers on debian unable to locate package

In UrBackup Appliance has Linux kernel 5.10.128. / Debian 10
when trying to update the header

apt-get install linux-headers-$(uname -r)


Couldn’t find any package by regex ‘linux-headers-5.10.128’

The problem is that it is not in the Debian repository. The latest it has are:

apt-cache search linux-headers
linux-headers-4.19.0-19-all - All header files for Linux 4.19 (meta-package)

Where to get the header updates for this kernel?

It’s a custom kernel ( ). Attached the headers.

linux-headers-5.10.128_5.10.128-1_amd64.deb (7.4 MB)

Thank you for Link.