Garmin TopoActive

Garmin uses OSM data for their TopoActive product. I thought that under the ODbl license they must distribute their product for free, but I can find no free distribution server for this data?

The ODbL license does not require that you provide your product for free. It does require that if you provide additional data (which is also available in OSM), you make that data also available as ODbL.

And the ODbL allows app display OSM data with external hotel data?

Yes, because the hotel data is a separate visible data set from a third party and not joined or insert into osm data.

I still don’t understand. The ODbL license says:

Share-Alike: If you publicly use any adapted version of this database, or works produced from an adapted database, you must also offer that adapted database under the ODbL.
Keep open: If you redistribute the database, or an adapted version of it, then you may use technological measures that restrict the work (such as DRM) as long as you also redistribute a version without such measures.

I read this to say that you can charge for your product, but you must also offer a version without DRM.

There is a difference between a derivative database and a collective database: