Trigger a public method in a public partial class with powershell

Hi together

Maybe someone can help me with this issue. I want to trigger a public method in a public partial class.
I only found solutions for static methods right now and I am not able to do this by my own. I hope someone can help me.

This is the class and method. I want to trigger the "public void RefreshTree(SPSite site)" method with powershell.

Namespace: MyCustomer.Base.Layouts.Base

public partial class TreeMaintenance : LayoutsPageBase
{

     public void RefreshTree(SPSite site)
     {
         ....
     }

}

Thank you for your advise!

Greetings Michael