PowerShell Visual Studio Project - sharing data across multiple .PS1 files

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Tool: Visual Studio, Visual Studio Code, PSScriptPad, PowerShell Module
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Hi Everyone, I am trying to create a new Forms UI for a fairly lengthy PowerShell Script. The Script was previously run at the PowerShell Command Line…

When I create a PowerShell Form Solution in Visual Studio 2022, there is an initial PowerShellFormProject1.ps1 for the Forms

How do I add additional .PS1 files and Share information between them and the PowerShellFormProject.ps1 code

Should I define $global: … variables?
Should I declare them in a .psm1 file?

Also, where should I put code that initializes the application prior to the Form coming up and likewise, where should I put the code to deconstruct everything I set up before I exit?

Thanks
Nikos