[Reclamação] Continua dando erro ERR_NGROK_8012 rs

Já tentei todas as respostas ditas aqui, e o erro continua dando
Traffic was successfully tunneled to the ngrok agent, but the agent failed to establish a connection to the upstream web service at http://localhost:4050. The error encountered was:

dial tcp 127.0.0.1:4050: connect: connection refused
Get help with this error

fiz exatamente o que ta escrito nesse topico https://cursos.alura.com.br/forum/topico-erro-ao-acessar-a-url-ngrok-free-app-493510.

# instalar as dependências
!apt-get update -qq
!apt-get install openjdk-8-jdk-headless -qq > /dev/null
!wget -q https://archive.apache.org/dist/spark/spark-3.1.2/spark-3.1.2-bin-hadoop2.7.tgz
!tar xf spark-3.1.2-bin-hadoop2.7.tgz
!pip install -q findspark
!pip install -q findspark
!pip install pyspark==3.4.0 
import os
os.environ["JAVA_HOME"] = "/usr/lib/jvm/java-8-openjdk-amd64"
os.environ["SPARK_HOME"] = "/content/spark-3.1.2-bin-hadoop2.7"
import findspark
findspark.init()
from pyspark.sql import SparkSession

spark = SparkSession.builder \
    .master('local[*]') \
    .appName("Iniciando com Spark") \
    .getOrCreate()
    
    !wget -q https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-amd64.zip
!unzip ngrok-stable-linux-amd64.zip

!pip install pyngrok
from pyngrok import ngrok

!ngrok authtoken {MEUTOKEN}

ngrok.connect('4050')

NING:pyngrok.process.ngrok:t=2025-08-05T23:40:15+0000 lvl=warn msg="ngrok config file found at both XDG and legacy locations, using XDG location" xdg_path=/root/.config/ngrok/ngrok.yml legacy_path=/root/.ngrok2/ngrok.yml
WARNING:pyngrok.process.ngrok:t=2025-08-05T23:40:15+0000 lvl=warn msg="can't bind default web address, trying alternatives" obj=web addr=127.0.0.1:4040