A Migration Passport is the item you move kingdoms with. How many you need depends on your season, your might and the target kingdom's status. Recommended is the cheapest, and only it grants a reward. Numbers are from the game client.
Your kingdom season
Target kingdom status
My might:
Rewards are granted only when migrating to a recommended kingdom — pick the “Recommended” status.
Data from the game client: migration slot counts and reward bundles per season and might bracket. Might in millions. · Full Viking Rise base →