Alex here, from the Shopify support team -
You can definitely convert your app into a Sales Channel! You can see more abouthow to do that here! You'll also want to review the requirements here:
I hope this helps! Please feel free to follow up here or with our Partner support team with any additional questions.
Alex | Support
We have an app on Shopify app listing for a long time and we have 100+ 5 star reviews also. Now we want to convert our app to a sales channel. But we checked Shopify Sales Channel Api's and scopes only works after uninstallation of current listed app from store and installation of new sales channel app. But we don't know how we can move our clients to sales channel app from current app. Please provide a solution so that we don't lose any reviews as well as clients.
Please help regarding this?
I'm in a similar situation of wanting to convert an existing app into a sales channel. I found the below quote in the documentation. Does this mean it's impossible to convert an existing app into a sales channel? I really hope not!
if your app has already been installed by Shopify merchants, then it can't be made a sales channel.