There is a visa scheme for these cases, please see my other comment.
Having to apply for a visa is the literal contradiciton to this.
The church/community group sponsoring to place with a volunteer family option seems novel too.
Otherwise as a refugee fleeing a war in Ukraine, I'm not really sure why the UK is a great option - there seem better, easier European choices, and as per up-thread we might do better to support that (even more).