input: 
  def submit_form_data() -> None:
      """
      Creates a Flask application that allows users to submit form data (Name, Email, Phone) and stores it in an SQLite database.
  
      >>> submit_form_data()
      # Run the Flask application, submit form with data: 'John Doe', 'john.doe@example.com', '123-456-7890'
      # Verify data is stored in the 'data.db' SQLite database.
      """
  
output:     
      from flask import Flask, request, render_template_string
      import sqlite3
  
      app = Flask(__name__)
  
      @app.route('/', methods=['GET', 'POST'])
      def index():
          if request.method == 'POST':
              name = request.form['name']
              email = request.form['email']
              phone = request.form['phone']
  
              conn = sqlite3.connect('data.db')
              cursor = conn.cursor()
              cursor.execute('''
                  CREATE TABLE IF NOT EXISTS users (
                      id INTEGER PRIMARY KEY AUTOINCREMENT,
                      name TEXT NOT NULL,
                      email TEXT NOT NULL,
                      phone TEXT NOT NULL
                  )
              ''')
              cursor.execute('INSERT INTO users (name, email, phone) VALUES (?, ?, ?)', (name, email, phone))
              conn.commit()
              conn.close()
  
              return 'Data submitted successfully!'
  
          return render_template_string('''
              <form method="post">
                  Name: <input type="text" name="name"><br>
                  Email: <input type="text" name="email"><br>
                  Phone: <input type="text" name="phone"><br>
                  <input type="submit" value="Submit">
              </form>
          ''')
  
      if __name__ == '__main__':
          app.run(debug=True)
  