After sellers have completed their registration, they will be redirected to the website provided by callback parameter, with the registered seller identity:

[https://your.desired.callback/uri?seller_id=285235&store_name=Their%20Store%20Name](https://your.desired.callback/uri?seller_id=285235&store_name=Their Store Name)

Your server should be able to recognized seller_id and store_name parameter.