Hey @MP_9597 - thanks for reaching out. At the moment, a product's customer facing URL isn't available to be sourced through the REST Admin API, however, one thing you could do is retrieve the handle of the product, which would allow you to reconstruct the product's URL. An example URL would look a little like this:
https://[yourstore].myshopify.com/products/[product's handle]
If you need to retrieve a store's domain, you can pull that from the shop object.
Hope this gives you some next steps to take a look at while building your app.
Cheers!
