Questions about Jabra Elite 4 Active

Hi. Are these headphones compatible with a Garmin Forerunner 165 Music watch? Thanks!

Is it possible to order just the charging case? I lost mine on the train.

I just bought these Earbods and am actually very happy with them. Except that these things keep falling out of my ears. That's probably not because of the Earbods, but because of my ears. Are there any holders or earrings or the like for this type, i.e. Jabra Elite 4 Active? Because buying new ones every time I use them is just too expensive. And it doesn't make much sense to glue them in or to hook them in with the Bostich. Thanks for any recommendations. (Except glue, nails or the like :-) )