Unable to get the app id and public key of a private app installed on Sandbox

Hello,

I'm on the Enterprise plan of the Support suite. I created a Sandbox and installed a private server-side app. Now, I want to get its app_id and public_key. Tried this curl command:

curl https://{subdomain}.zendesk.com/api/v2/apps.json \
-u {email_address}:{password}

Tried it with both my sandbox subdomain and main account subdomain, but could not find my app in the verbose response.

But managed to get the app_id from the image url of my installed app's icon by following this post: https://support.zendesk.com/hc/en-us/articles/360042558154-How-can-I-find-an-App-ID-in-my-Zendesk-instance-

However, to get the public key, when I use this app_id with the following curl command:

curl https://{subdomain}.zendesk.com/api/v2/apps/{id}/public_key.pem \
-u {email_address}:{password}

I'm not getting any response. Will be grateful for any comments or solutions!