1)Plz send url for brand register?
>>>There is no such URL for brand registry. Go to Amazon seller central and create a ticket regarding register on Amazon.
2) getting problem in register on Amazon as not add new product button in inventory / add product?
>>>I guess you want to know how to add product to your inventory. I have created a gif file about how you can add product to Amazon seller central.
Log in to seller central>click on Inventory tab> Select Add product. Then add product window will open.
GIF file>>> https://tinyurl.com/ycvc3zle
Let me know if you have asked same thing or have other queries.