Installing older kernels

It doesn’t work:

[user@dom0 ~]$ sudo qubes-dom0-update kernel-4.19.163
Using sys-whonix as UpdateVM to download updates for Dom0; this may take some time...
fedora/metalink                                             | 6.4 kB  00:00     
fedora                                                      | 4.3 kB  00:00     
fedora/primary_db                                           |  26 MB  00:46     
qubes-dom0-current                                          | 3.8 kB  00:04     
qubes-dom0-current/primary_db                               | 426 kB  00:02     
qubes-dom0-current-testing                                  | 3.8 kB  00:02     
qubes-dom0-current-testing/primary_db                       | 355 kB  00:02     
qubes-dom0-security-testing                                 | 3.8 kB  00:00     
qubes-dom0-security-testing/primary_db                      | 774 kB  00:05     
qubes-dom0-unstable                                         | 3.0 kB  00:00     
qubes-dom0-unstable/primary_db                              | 175 kB  00:01     
qubes-templates-community                                   | 3.0 kB  00:00     
qubes-templates-community/primary_db                        | 8.0 kB  00:00     
qubes-templates-community-testing                           | 3.0 kB  00:00     
qubes-templates-community-testing/primary_db                | 4.8 kB  00:02     
qubes-templates-itl                                         | 3.0 kB  00:00     
qubes-templates-itl/primary_db                              | 6.9 kB  00:00     
qubes-templates-itl-testing                                 | 3.0 kB  00:00     
qubes-templates-itl-testing/primary_db                      | 5.7 kB  00:01     
updates/metalink                                            | 6.0 kB  00:00     
updates                                                     | 4.7 kB  00:00     
updates/primary_db                                          |  12 MB  00:21     
--> Running transaction check
---> Package kernel.x86_64 1000:4.19.163-1.pvops.qubes will be installed
--> Finished Dependency Resolution
kernel-4.19.163-1.pvops.qu 97% [=============kernel-4.19.163-1.pvops.qu 97% [=============kernel-4.19.163-1.pvops.qu 97% [=============kernel-4.19.163-1.pvops.qu 97% [=============kernel-4kernel-4.19.163-1.pvops.qubes.x86_64.rpm                    |  49 MB  04:31     
Successfully verified /var/lib/qubes/dom0-updates/packages/kernel-4.19.163-1.pvops.qubes.x86_64.rpm
Qubes OS Repository for Dom0                                   72 MB/s |  73 kB     00:00    
No package kernel-4.19.163 available.
Error: Unable to find a match.
[user@dom0 ~]$ sudo dnf downgrade kernel-4.19.163
Qubes OS Repository for Dom0                                                                                                                                   72 MB/s |  73 kB     00:00    
Error: conflicting requests
(try to add '--allowerasing' to command line to replace conflicting packages)