Hello Petra,
I attach the lik of a shop that sells allulose and ships all over Europe: https://es.iherb.com/pr/health-garden-all-natural-allulose-sweetener-14-oz-397-g/106072?gad_source=1&gclid=CjwKCAjw9IayBhBJEiwAVuc3fvYGfCgEUS09-HO3iHhVDIQQEpKIefIKETgR-ZtrpyaaA5bzRo_38hoCyi8QAvD_BwE&gclsrc=aw.ds
Don’t worry, you can substitute this ingredient for oligofructose in many recipes.
Oligofructose: I attach the link of another supplier where you can find this ingredient: https://www.beneo.com/es/beneo-contact?sec=general
If you have any other questions, let me know.
Have a nice day!