Currently, it doesn't look like the FireTV is available on Amazon.ae except from 3rd party sellers. Check directly with CS on the UAE site to verify whether or not the one you purchased can be used in UAE. There is no help page for FireTV or Fire stick on the UAE site.
Scroll down on the left to the "Need more help?" link, then choose "Contact us."
Eligible customers outside these countries can use Fire TV Stick Basic Edition to access streaming content from Prime Video. Content available from Prime Video varies by country and does not include purchases or rentals.