Hello @Mahdhi Ali ,
Welcome to our Microsoft Q&A platform!
Portable Class Libraries (or PCLs) are now unsupported in VS 2019. It doesn't support to run another application in current project programmatically. We can only reference another project to call some function code.
Check the doc: https://learn.microsoft.com/en-us/visualstudio/ide/managing-references-in-a-project?view=vs-2019
Best Regards,
Jarvan Zhang
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