Independent fiori app but multitenant cap app

I was trying to create an app as mentioned in the Approach 2 here :

https://blogs.sap.com/2021/12/03/sap-btp-capm-the-micro-services/

That is, an independent fiori app built which talks to CAP app, all I am worried about is how to implement multitenancy in this architecture. How do I pass the tenant Id from an independent fiori app to a multitenant CAP app.

I was planning to add this fiori app to a portal service or launchpad service ( as a standalone app ). CAP apps to be deployed with standalone approuters as well separately.

Could someone shed some light to this?