Why can't I install my custom app on a different account?

I am new to shopify app developement and I am trying to develop an app and share it to another Account.

These are the stores connected to my accont

I have created a custom app in the ‘aubergine test app’ store and converted the distribution to ‘Custom distribution’ following this article:

https://shopify.dev/docs/apps/distribution/select-distribution-method#install-a-custom-app-on-multiple-stores

When I use the link generated, and try to access/install the app to the monicaandandy store it gives me the following error.

I think the issue can be with App setup → URLs section or ngrok.

Please help me out.

Currently all I have done is,

  1. Created the app using npm init @Shopify_77 /app@3.47.5

  2. Created a new app for the code during preview

  3. Went to Partners account → All apps → ‘name of my app’ → Distribution → changed it to custom app

If there is some step by step guide to do this, including the ngrok (if it is needed) integration and all, please share! Thank you!!