How to export swiftUI view as a PDF file on macOS

Question

I need to export a swifUIview as PDF file on macOS big sur. Here is the function I am using:

func exportPDF() {
        let testView = TestView()
        let hostingView = NSHostingView(rootView: testView)
        hostingView.frame = .init(origin: .zero, size: .init(width: 800, height: 1200))
        do {
            let pdfData = hostingView.dataWithPDF(inside: hostingView.bounds)
            
            let savePanel = NSSavePanel()
            savePanel.allowedFileTypes = ["PDF"]
            savePanel.canCreateDirectories = true
            savePanel.isExtensionHidden = false
            savePanel.allowsOtherFileTypes = false
            savePanel.title = "Save your text"
            savePanel.message = "Choose a folder and a name to store your text."
            savePanel.nameFieldLabel = "File name:"
            let response = savePanel.runModal()
            if response == .OK {
                let urlDuPDF = savePanel.url
                guard let urlDuPDF = urlDuPDF else { return }
                try pdfData.write(to: urlDuPDF)
            }

This function runs very well with this simple struct :

struct TestView: View {
    var body: some View {
        VStack {
            Text("Test view for PDF")
            Text("Test view for PDF")
          
        }
    }
}

Unfortunately, it doesn't run with this struct (with image/width: 300, height: 300)

struct TestView: View {
    var body: some View {
        VStack {
            Text("Test view for PDF")
            Image("eau")
        }
    }
}