The DW article Ukraine is using Elon Musk's Starlink for drone strikes about the use of Starlink to provide internet in Ukraine is suggesting that it is playing a role in, e.g., the way president Zelenskyi is able to make live calls to so many nation's governments, parliaments or the UN among other things. It has also become a target for the Russian military. Would Ukraine be able to communicate globally without the use of Starlink? And I am not even mentioning its supposed role in drone strikes.
Mykhailo Fedorov (Vice Prime Minister of Ukraine and Minister of Digital Transformation of Ukraine) made the initial public appeal to Elon Musk about Starlink:
@elonmusk, while you try to colonize Mars — Russia try to occupy Ukraine! While your rockets successfully land from space — Russian rockets attack Ukrainian civil people! We ask you to provide Ukraine with Starlink stations and to address sane Russians to stand. https://twitter.com/FedorovMykhailo/status/1497543633293266944
He had since tweeted multiple times on topic. His tweets cover Starlink use in cases where normal communication infrastructure is unavailable or destroyed.
As of early May he shared the number of 150K active daily users:
Rough data on Starlink's usage: around 150K active users per day. This is crucial support for Ukraine's infrastructure and restoring the destroyed territories. Ukraine will stay connected no matter what. https://twitter.com/FedorovMykhailo/status/1521115986711175168
That isn't huge on the scale of Ukraine's ~41 millions (under normal circumstances) population, but probably significant if strategically applied at war time.
The military applications are occasionally reported by news as generally happening, but with no meaningful details (as it should be during war).