I thought Czech was a pro drop language for verbs? No need for ‘my’ as ‘jsme’ makes that perfectly clear. Maybe in this case it’s for extra emphasis?
Se the Tips and notes of skill To be (singular)
why sometimes you have to put "my" and others not? still don't get it
You do not have to. It is usually added for emphasis.
Dekuju vam, Honzo!
It has refused a small typo above and instead insists the following is correct:
"Ano, jsme hoši."