You can sign up for FLX either online on www.footlocker.nl/FLX or in the stores in the Netherlands (Foot Locker & Kids Foot Locker).
Please note, if you sign up in store, you will need to complete your registration online within 365 days of the date you signed up in store. If you do not complete your registration within this time, you will not be able to redeem any points and your account will be deactivated.