How do I send user inputs to a database using the forms feature in swift UI? [closed]

I can't set the database up for you, as each database has its unique ways of doing so. However, I am giving you a basic structure that would help you link your SwiftUI view to the back-end(your database).

Setting up your form

import SwiftUI

struct ContentView: View {
    @State var firstName = ""
    @State var lastName = ""
    @State var age = ""
    
    var body: some View {
        TextField("Enter First Name", text: $firstName)
        TextField("Enter Last Name", text: $lastName)
        TextField("Age", text: $age)
        Button(action: {
            addUser(firstName: firstName, lastName: lastName, age: Int(age) ?? 0)
        }) {
            Text("Save to database")
        }
    }
}

Saving result to back-end:

import CoreData

func addUser(firstName: String, lastName: String, age: Int) {
/*   
     code here would be using Core Data structure
     do not copy paste, only used as reference
*/
    let newUser = User(context: context)
    newUser.firstName = firstName
    newUser.lastName = lastName
    newUser.age = age
    
    do {
        try context.save()
        print("Successfully saved to Core Data.")
    } catch {
        print(error.localizedDescription)
    }
    
}

Keep in mind that you would have to do your own research on how to save results using your own database. The code in addUser() would not work if you are using something other than Core Data. In your case, I would suggest you to try Firebase and perhaps, you could use Firebase Firestore as it seems like it suits your needs.