In your partner dashboard find the app you want to install. On the app Overview page click the green Choose distribution button. Choose Custom distribution then continue by the clicking Select. This will allow you to select which single store you want to install on and generate a link.
Topic summary
Main issue: A developer wants to build a Checkout UI app and install it only on their own store without hosting it publicly or listing on the Shopify App Store.
Solution provided: In the Shopify Partner Dashboard, open the app’s Overview page, click the green “Choose distribution” button, select “Custom distribution,” then click “Select.” Choose the single target store to generate a private install link.
Outcome: This approach enables installing the app on a live store via a generated link without public distribution. No disagreements surfaced, and the guidance appears to resolve the request; no outstanding questions noted.