Migrate centos7 to rocky9

Hi,
Is there a solution to migrate a centos7 to rocky9, without going through centos8 please ?
Regards.

You are recommended to backup configuration/data and restore it as needed on a new Rocky Linux 9 machine. There is no direct migration path nor is there a supported upgrade path. As there are many differences between 7 and 9, you will need to take care of analyzing your configuration files and comparing them to the defaults on 9 and ensure that they will still be applicable or work.

OK thanks, but is there a way to migrate first to rocky8 and after to v9 ?

The same recommendation: fresh install, deploy relevant and appropriate config, and transfer user data.
But why do that first to 8 and the to 9, if one can do it directly to 9?

You seem to desire to in-place convert one distro to a different distro. The desire is understandable, but a need for “recovery procedure” is also very real – even when nothing bad happens. This – transfer of data and config to fresh install – is an opportunity to test that procedure.