Does the Galaxy S10 support eSIM?
No. The Galaxy S10 (2019) has no eSIM hardware, so travel eSIMs will not install on it. A physical local SIM or hotspot from a companion device are the alternatives.
Every model in this line from 2020 onwards does support eSIM, so an upgrade brings travel eSIMs with it.
Check it on your phone in ten seconds
Settings, then Connections, then SIM manager, then Add eSIM. If that option appears, your Galaxy S10 is ready.