Activating a customer programmatically

[intelli-ua]

Hi,

In the public app I'm working on there is a need to activate a customer using Shopify APIs. I've made a research on 3 main APIs:
1) REST API - only allows to generate account activation URL or send an account invite (email);
2) GraphQL API - only allows to generate account activation URL;

3) Storefront API - allows to activate customer and even activate by URL (which allows to set the password for a customer who don't have it yet) - this is very good.

So the option 3 (Storefront API) looks like what I need. But it turned out that if I'm building a regular Public app (not a Private one and not a Sales Channel) I can not use Storefront API endpoint I need:

So if my app is not going to be a Sales Channel, there is no option for me to use a Storefront API (even though I need not sales channel related endpoint to be used and don't want to provide any sales channels features in my app). Can anyone tell if it is anyway possible to request Storefront API access in any way, or suggest an alternative for activating a customer account?

Thanks in advance!