Failed to build the SnapAPI kernel module

Hi,

Trying to install Acronis Cloud backup agent on a Ubuntu 16.04.5 LTS VPS (no gui, console only) but I get the following error:

Installation of the Backup Agent packages has finished.
The following problems occurred:
- failed to build the SnapAPI kernel module. Operations with disk-level backups will not be available.
- failed to load the SnapAPI kernel module.
See 'HOWTO.INSTALL' for further instructions.

Fine, I read the HOWTO.INSTALL. Ran some commands but stuck now:
 

root@vps:~# uname -r
3.13.0-042stab130.1

root@vps:~# sudo apt install linux-headers-`uname -r`
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package linux-headers-3.13.0-042stab130.1
E: Couldn't find any package by glob 'linux-headers-3.13.0-042stab130.1'
E: Couldn't find any package by regex 'linux-headers-3.13.0-042stab130.1'

apt-cache search linux-headers doesn't show any 3.x, only a long list of different 4.x

How do I solve this problem, how do I get this SnapAPI going?