The operation couldn't be completed. client error

[tayabsoomro]

Hello, I am having some difficulty trying to set up payment system to my react-native application. I followed the instructions on adding URL target in Xcode as well as to match that URL target when initializing the BTClient:

BTClient.setupWithURLScheme('sandbox_w365w55p_3wb7p9q4rk8hv2h2',"com.invertase.MyApp.payments")

When I click on the button "PayPal Check out", it shows the following alert box:

Please help?