input: 
  from flask import Flask, render_template, request, redirect
  import sqlite3
  
  def submit_form_data_to_db() -> None:
      """Submit form data containing Name, Email, and Phone to a SQLite database using Flask.
  
      Example:
      for 
      home() == render_template('index.html')
      submit(name='John Doe', email='john.doe@example.com', phone='1234567890') == redirect('/')
      """
      app = Flask(__name__)
  
      @app.route('/')
      def home():
          return render_template('index.html')
  
      @app.route('/submit', methods=['POST'])
      def submit():
          name = request.form.get('name')
          email = request.form.get('email')
          phone = request.form.get('phone')
          
          conn = sqlite3.connect('data.db')
          cur = conn.cursor()
          
          cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
          conn.commit()
          
          return redirect('/')
          
      if __name__ == '__main__':
          app.run(debug=True)
  
output:     conn.close()