My webcam is not showing using Tkinter in a while loop

Question

i have this problem where my webcam is not showing using Tkinter,i want to make a GUI where the person click the webcam button and start detecting sign languague, works only when the function "mostrarWebcam" is in the while loop, but in that condition, the webcam dont show up. I hope you can help me whit this issue.

def mostrarWebcam():
    global cap
    sequence = []
    sentence = []
    predictions = []
    threshold = 0.5

    while cap is not None:

        ret,frame = cap.read()
        if ret == True:
            frame=imutils.resize(frame,width=700,height=1200)
            frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)

            frame,results = mediapipe_detection(frame,holistic)
            frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            draw_styled_landmarks(frame,results)

            keypoints = extract_keypoints(results)
            sequence.append(keypoints)
            sequence = sequence[-50:]

            if len(sequence) == 50:
                res = modelo_cargado.predict(np.expand_dims(sequence, axis=0))[0]
                print(actions[np.argmax(res)])
                predictions.append(np.argmax(res))
            
            
        #3. Viz logic
                if np.unique(predictions[-10:])[0]==np.argmax(res): 
                    if res[np.argmax(res)] > threshold: 
                    
                        if len(sentence) > 0: 
                            if actions[np.argmax(res)] != sentence[-1]:
                                sentence.append(actions[np.argmax(res)])
                        else:
                            sentence.append(actions[np.argmax(res)])

                if len(sentence) > 5: 
                    sentence = sentence[-5:]

            # Viz probabilities
                frame = prob_viz(res, actions, frame, colors)

            frame = cv2.rectangle(frame, (0,0), (640, 40), (245, 117, 16), -1)
            framex = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            im   = Image.fromarray(framex)
            img = ImageTk.PhotoImage(image = im)

            lblVid.configure(image=img)
            lblVid.image = img
                    
            lblVid.after(10, mostrarWebcam)
        else:
            lblVid.image=""
            cap.release()