How to get my service provider to send me a sim card to fit in an iphone?

Need this quickly please and no stupid answers

It Is a called a nano sim, they usually have a website where you can request sims, if not then they might have an email u provide your address and name…

however unless you unlock your phone you won't be able to use giffgaff, lyca, vectone etc… Or other names similar…

without unlocking i'm reasonably sure you can use 3, Tmobile, ee, orange, 02… Also some shops sell them cheap make sure you buy nano, or if they know how to cut a micro sim for you