When upgrading to SharePoint Server 2019, or SharePoint Server Subscription Edition you have to perform an interim upgrade to SharePoint Server 2016. In this environment you’ll upgrade the SharePoint components in preparation for the upgrade to 2019 or the Subscription Edition.
This interim step can be completed on a single server so you don’t have to create a multi-server farm for this short term solution. However to upgrade to a single server farm, as you can imagine there are some steps necessary to ensure the upgrade process is successful which in turn will ensure your next upgrade is successful.
For more information on this SharePoint Server 2016 single server upgrade, as well as software requirements, which includes SQL Server, the upgrade process, and links to assist in the upgrade to SharePoint Server 2019, or SharePoint Server Subscription Edition, please visit TekkiGurus and view my article Getting to SharePoint 2016 Single Server from SharePoint 2013.
