How do I get user to return to main page after popup activated in pysimpleGUI

Question

I'm trying to validate user input. A popup is triggered when incorrect data entered. My app then closes but I want it to return user to main page to modify input. Tks, Ian

while True:
    event, values = window.read() #values is a list in Python
    
    if event  == 'Exit':
        break
    elif event == 'Submit':
        #input_valid = False
        #while not input_valid:
            validation_result = validate_inputs(values) #returns array of [is_valid[bool],invalid_values[array]
            if validation_result[0]:#if True
                string_of_rpt_date = calculate_repeat_date(values) #function takes interval value inputted and returns next repeat as sting
                c.execute("INSERT INTO PATIENT(SURNAME,FIRST_NAME,ADDRESS,DOB,MOBILE,PPS,DOCTOR,REPEAT_INTERVAL,REPEATS_LEFT,REPEAT_DATE) \
                         VALUES (?,?,?,?,?,?,?,?,?,?)",(values['-SURNAME-'],values['-FIRST_NAME-'],values['-ADDRESS-'],values['-DOB-'],values['-MOBILE-'],values['-PPS-'],values['-DOCTOR-'],values['-REPEAT_INTERVAL-'],values['-REPEATS_LEFT-'],string_of_rpt_date))
                conn.commit()
            
                c.execute("SELECT * FROM PATIENT WHERE REPEAT_DATE = ?", (string_of_today,)) #checks database to see if any patients repeat date is today
                results = c.fetchall()
                for row in results:
                    mobile = row[4]
                    first_name = row[1]
                    repeats_left = row[8]
                    repeats_left = repeats_left -1
                    c.execute("UPDATE PATIENT SET REPEATS_LEFT =? WHERE FIRST_NAME = ?", (repeats_left,first_name,))
                    conn.commit()
                    print(mobile)
                    print(repeats_left)
                    print(first_name)
                    print(results)
                #flow_twilio(first_name,repeats_left) # this function sends msg via twilio 
                                                 # to let patient know repeat is due 
                                                 # and how many repeats are left"""
                conn.close() 
            
                #whatsapp_twilio(mobile, first_name, repeats_left )
                #text_twillio(mobile, first_name, repeats_left)
            
            
                sg.popup(values['-FIRST_NAME-'] + ' ' + values['-SURNAME-'] + ' was added to the database')
                
            else:
                error_message = generate_error_message(validation_result[1])
                sg.popup(error_message, auto_close=True)#popup of elements of invalid_values array
               
    if event == sg.WIN_CLOSED:
        break

    
    window.close()

I tried adding a while loop just after the submit button is pressed as follows elif event == 'Submit': but this didn't work either.

I'm relatively new to coding so not sure where to go next. Any help appreciated