Forge unlicensed users email

We have implemented a Forge App, which uses a multi-tenant back-end. Essentially that means, we have to identify for each request that is sent to the backend, the company from whose portal this request came from. For jira users we can do this by relying on their email, from which we read their email domain. On the other hand, for jira customers, that might use our Forge App, we can’t read their email, because they are not licensed users. This is described here. How can we read a customer’s own email ? As of now we can’t rely on asUser described here](, since customer isn’t a licensed user.