What sort of licence do you need to ride a 50cc Scooter?

Can I use a UK provisional or do I need to get a Spanish one?

The spanish law allows to drive up to a 125 cc (link needed) scooter without getting the “A” license (motos). Being a EU citizen -and having the uk equivalent for cars during 3 years- you shouldn’t have any problem.
Sorry, just realised you had a prov licence. Don’t think you can use that.