Jesus wept.
Ukrainians are technically not 'travelling through' other safe countries, given they are flying directly to the UK (likely from Poland where they first sought sanctuary from war).
Anyone who travels from Syria via Turkey and across most of Europe, where they could claim sanctuary, to end up in Northern France in order to make an illegal crossing of the channel, is most likely not a refugee, but more likely to be an economic migrant - albeit one that has been coached to claim asylum if they get caught.
For you, this is probably rocket science, for everyone else it's a fairly simple concept.