How to upgrade GNUCash

I have installed GNUCash on Zorin OS 15.3. Unfortunately it is GNUCash version 2.6.19. The latest GNUCash version is 4.2 and GNUCash updated their database format from version 3. Since my wife also accesses the programme from her Windows laptop (the database is on a NAS server) the database is version 3 which cannot be read by GNUCash 2.6.19.

So my question is, how do I upgrade GNUCash on Zorin OS to a version beyond version 3?

Or do I have to find another Linux distro that had a more recent version?

You can try the method here:
I recommend that you first remove your existing GNUCash using Synaptic before trying those steps.

That worked!

Thanks very mcuh.