Hi @adil ,
As per my knowledge, the Project Server 2019 installation is now a part of the SharePoint Server 2019 installation. Project Server 2019 now runs as a service application in SharePoint Server 2019, and does not require a separate installation. After upgrading to SharePoint Server 2019, you have to copy and move your databases and attach and upgrade your SharePoint Server 2016 content database.
You can find detailed steps at: Project Server 2019 upgrade steps.
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