@laurenwatral Thanks for reaching out!
It looks like Glerups does make that model of slipper in a size EU 35. Unfortunately, REI does not carry that size. We do, however, have the ability to order a product from one of our vendors that is not normally carried by REI. That process is called a 'special order'. If you would like to place a special order, you need to go into your local REI store and begin the process there. Vendor participation, product availability, shipping timeline, and shipping cost is dependent on the brand, so please be aware there may be some variability there.
Hope this helps!