Resolved: python tkinter updating the combo box programmatically

import customtkinter
from ConnexLink import findcomports, recievesignal, closeserialport
import serial

customtkinter.set_appearance_mode("light")  # Modes: "System" (standard), "Dark", "Light"
customtkinter.set_default_color_theme("blue")  # Themes: "blue" (standard), "green", "dark-blue"

app = customtkinter.CTk()
app.geometry("500x500")
app.title("Connex Link")

def runfindcomports(afterfirstrun=True):
  ports=[]
  for info in serial.tools.list_ports.comports():
      port1=str(info)#sets the com port to port1
      ports.append(port1[0:4])
  if afterfirstrun:
    combobox_1['values']=ports
    print('why is it not working')
    print(ports)
  return(ports)
ports=runfindcomports(False)

onoroff = False
def onswitch():
  global onoroff
  global ser
  if onoroff:
    onoroff=False
    ser.close()
  else:
    onoroff=True
    print('on')
    ser = serial.Serial(combobox_1.get(),9600,timeout=2)  # open serial port
    
  
frame_1 = customtkinter.CTkFrame(master=app)
frame_1.pack(pady=20, padx=60, fill="both", expand=True)

label_1 = customtkinter.CTkLabel(master=frame_1, justify=customtkinter.LEFT,text='Vibrac')
label_1.pack(pady=10, padx=10)

combobox_1 = customtkinter.CTkComboBox(frame_1)
combobox_1.pack(pady=10, padx=10)
combobox_1.set("Select Com Port")
combobox_1['values']=ports

switch_1 = customtkinter.CTkSwitch(master=frame_1, command=onswitch,text='receive',)
switch_1.pack(pady=10, padx=10)

button_1 = customtkinter.CTkButton(master=frame_1, command=runfindcomports,text='refresh',)
button_1.pack(pady=10, padx=10)

text_1 = customtkinter.CTkTextbox(master=frame_1, width=300, height=300)
text_1.pack(pady=10, padx=10)

def textfilter(bytes):
  text=str(bytes)
  text=text[2:]
  text=text.split('\\',1)[0]
  return text

def printline():
  global onoroff
  if onoroff:
    line = ser.readline()
    if len(line) > 2:
      text_1.insert("end",textfilter(line)+'\n')
  app.after(500,printline)


app.after(500,printline)
app.mainloop()

combobox_1.configure(values=ports)