ASIN stands for Amazon Standard Identification Number. It’s a unique, 10-character alphanumeric used for product identification within Amazon. It’s a lot like a barcode or serial number. Each artist, album, track, playlist, and retail item within Amazon has an ASIN.

You can locate an Amazon ASIN number in a few different places: product web address, product details, or by using a software tool for ASIN lookups. On Amazon Music an ASIN can be found in the product deep link under Share and is located after the qualifying text artists/, trackAsin= or albums/ as seen with the example below.

Source: Amazon Music for Artists - FAQs