There are two ways you can buy the pass:
Navigate to the game’s store page and select “Crow’s Fortune”
From the game’s home screen, tap your Player Name on the right of the screen, this will send you to the subscription section of the store.
You’ll know if your subscription is active by either seeing the word “active” in the subscription menu, or by checking if the subscription icon is lit up next to your Player Name on the game’s home screen.
Please note that the pass will NOT be automatically be renewed when it has expired - you'll need to repurchase it.