you should be able to simply add the JSD application and then move the project to JSD.
in your JSW project go to project settings>details and change the Project type. I haven't done this but...according to the documentation it should work.
you mentioned in the original question that you were willing to create a new JSD. If it is possible/acceptable then you could do so adding the application to your current JSW instance. If that is not possible then your best bet is to export the issues from JSW and import into your JSD instance. A bit tedious but certainly doable.
Something to ponder/try if the export/import from JSW to JSD is challenging. Assuming you want to continue w/ separate JSD instance from your current JSW. I wonder if it might work out better to:
Hello, Community! My name is Gosia and I'm a Product Manager on Jira Server and Data Center here at Atlassian. Since 2002 when we launched our public issue tracker, jira.atlass...
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