Login with LinkedIn is returning "The application is disabled"

I'm trying to set un a Log in with LinkedIn button. I followed all the steps in this post:

https://www.digitalocean.com/community/tutorials/django-authentication-with-facebook-instagram-and-linkedin#step-4-%E2%80%94-linkedin-authentication

The only difference is that my Authorized redirect URLs for your app is this one:

http://localhost:8000/auth/complete/linkedin-oauth2/

I added the keys in my backend, and I also added the "Sign In with LinkedIn" option inside the "products" tab.

But I'm still getting this message when I try to Log In:

I don't know if this is helpful, but I'm getting this error in the console: Uncaught TypeError: Cannot read property 'textContent' of null

I have no idea what is going on here, I can't find someone with the same problem.

Do you have any clue what can I be doing wrong?