Questions about Shimano Slx Cs-M7000

The freewheel is not in the cassette, it should be in the hub. I don't know whether the cassette fits the Stromer ST1, but if an 11-speed cassette is available, the SLX CS-M7000 should fit.

Unfortunately, I couldn't find this information anywhere at the manufacturer's or on the web in general. With a bit of luck, someone else will answer your question.

Shimano hg cg h601 11 speed also fits e bike and can be ordered here