How do you active xp boost tickets?

[啊怎麼都沒腳步聲]

as title :U thanks

[Windzor]

When you start a match, at the character select screen you'll see a green "XP Boost" button in the top-right, click that to see how many tokens you have and to spend one on that match.

You have to use the tokens first, once you're out of tokens you can spend Salvage on more boosts instead.