This is the 71st most frequent Czech word.
ukrajině
The Czech word "ukrajině" means "to Ukraine" or "in Ukraine" (dative or locative case).
In this sentence, 'Ukrajině' is in the locative case, indicating the location where the action took place.
Byl jsem na Ukrajině minulý rok.
I was in Ukraine last year.
Here, 'Ukrajině' is again in the locative case, describing the place where the help is directed to.
Pomáháme lidem na Ukrajině.
We are helping people in Ukraine.
In this instance, 'Ukrajině' is once more in the locative case, describing the place related to the situation.