How to make Picker's selected value the first choice

I'm trying to my macOS app which UI was written in StoryBoard into SwiftUI. I am beginner of SwiftUI...

I have swiftUI Picker like the following:

import SwiftUI

struct MessageAreaView: View {

// opponent name
@ObservedObject var anOpponentName: ShareValues

// menu type picker selection
@State var selectedMenu: String = ""

// menu type picker content
let defaultMenus = ["Hi. How about a game?", "Good luck!", "I give in.", "Thank you for the game.", "Let’s play again sometime.", "My hand slipped. May I undo?", "Hello.", "Goodby.", "Thanks."]

var body: some View {

	// Menu type picker
	Picker(selection: $selectedMenu, label: Text(""), content: {
	    Text("Select Item").tag("") // To avoid "picker: the selection "" is invalid..."
	    ForEach(defaultMenus, id:\.self) { aMenu in
	       Text(aMenu)
	    }
	})
	.pickerStyle(.menu)
	.onChange(of: selectedMenu, perform: { selected in
	    	        
        if !(selected == NSLocalizedString("Select Item", comment: "Select Item")) {
            
            let anOpponent = anOpponentName.anOpponentName
            
            let commentToSend = NSString(format: "TELL %@ %@\r\n", anOpponent, selected) as String
            mySocket.sendMessage(message: commentToSend)
        }
        // I'd like to set selectedMenu to "Select Item" here...
	})
	.frame(width:470)
}

I'd like to set selectedMenu to "Select Item" (The first item of picker selection).
WIth NSPopUpButton, there is selectItem(at: index), but I can't find out a way to do like so in SwiftUI Picker...
How to I do it?

First of all the comparison selected == NSLocalizedString("Select Item" will always be false because "Select Item" is the displayed title of the menu item but not the value/tag which is an empty string.

Second of all Swift provides a more convenient way to format strings called String Interpolation.

To reset the picker to "Select Item" set the property selectedMenu to an empty string.

.onChange(of: selectedMenu) { selected in
                
    if !selected.isEmpty {
        let anOpponent = anOpponentName.anOpponentName
        let commentToSend = "TELL \(anOpponent) \(selected)\r\n"
        mySocket.sendMessage(message: commentToSend)
        selectedMenu = ""
    }
}