Oauth error invalid_request: Could not find Shopify API application with api_key

[shameerkashif]

I've been trying to work it out for past couple hours. I came across other solutions but none work.
This happens when i perform install app step from my custom app.
The url is missing the client_id parameter which should be the API key i guess. After redirection from my custom app, the url is:

https://mystore.myshopify.com/admin/oauth/authorize?state=161427903307200&scope=&client_id=&redirect...

I don't understand what i did wrong. I simply followed this tutorial:

https://shopify.dev/tutorials/build-a-shopify-app-with-node-and-react/embed-your-app-in-shopify

Can somebody tell me where did i go wrong?