Paypal authorize popup wrong enviroment when checkout button was clicked.

[loint]

I'm following document https://developer.paypal.com/docs/integration/direct/express-checkout/integration-jsv4/server-side-R...

to integrate on my website. However, when I click into payment method, paypal authorize popup show wrong enviroment. I configured sandbox enviroment but paypal redirect page to

https://www.paypal.com/cgi-bin/webscr?cmd....

instead of

https://www.sandbox.paypal.com/cgi-bin/webscr?cmd....

My client side code integrated such as :

Any help, Thank you!