Xcode – How do I avoid app zoom when keyboard opens?

When I click my SwiftUI text field and the keyboard opens, the app zooms out (shown in video).

I have two questions about this behaviour:

1. Why does this happen?
2. How do I avoid this happening?

Here is my code:

struct BestillView: View { // This view is put inside a tab view with .ignoresSafeArea
    @State var navn = ""
    @State var varsling = true
    
    var body: some View {
        NavigationView {

            ZStack {

                Color("BackgroundColor")
                    .ignoresSafeArea()
                VStack {
                    Image("Liquid") // This is my image overlayed on the background, i suspect this may be the only element that actually gets zoomed out
                        .resizable()
                        .aspectRatio(contentMode: .fit)
                        .ignoresSafeArea()
                    Spacer()
                }
                

                VStack {
                    ZStack(alignment: .leading) { // This is where the text field i'm having trouble with is
                        Color("UnselectedColor")
                            .frame(height: 50)
                            .cornerRadius(20.0)
                        if navn.isEmpty { // I have a separate text element as the placeholder text so i can give it a custom color
                            Text("Navn")
                                .foregroundColor(Color("AccentColor"))
                                .padding()
                        }
                        TextField("", text: $navn)
                            .padding()
                    }
                    .frame(width: 300)
                    


                    Spacer()
                        .frame(height: 20.0)
                    
                    // I removed the rest of my code, I don't think it should be necessary in this question - it's only a NavigationLink and a Toggle
                }
            }
        }
    }
}