Woocomece paypal advanced error

Hello i bought woocommerce paypal advanced but i dont know how to configure it here is the things i had done
1) created paypal sandbox account
2)created seller account and marked it as pro
3)created buyer account

than i added merchant login in admin (sellers email)

mark sandbox on.

than when i try to buy product from front end i get error

Error: “There was an error processing your order – User authentication failed”

i dont know what further steps requires?

is there any manager.paypal.com registration required.

i need detail guide to setup it woocomece paypal advanced