How do I solve Shopify's Oauth matching hosts error?

I am building a small backend as a learning exercise with node.js, express, typescript, and the shopify API.

My server runs fine and successfully goes to the home “/” page, but when I try to authorize at

https://[base-url]/auth?shop=autodidack.myshopify.com

I get the following error:

Oauth error invalid_request: The redirect_uri and application url must have matching hosts

I have tried this with a base-url of localhost:3000 and with an ngrok tunnel and get the same error each time. I can also confirm that my param is named shop and my store domain is [provided if anyone ask]

AI is telling me that I have to set my app_url to

https://[base-url]/auth?shop=autodidack.myshopify.com

and my redirect URLs to

https://[base-url]/auth?shop=autodidack.myshopify.com/auth/callback

The only place to do this is in the Shopify dev dashboard by setting a new version. I did this and still get the same error.

What am I missing?

Thanks in advance.