Why Received status code 400 from server ?

[Zuowxing]

I just want to run 'app'，But Gradle build error : Could not resolve com.trustwallet:wallet-core:2.9.5。...Username must not be null！So , I set the 'gpr.user'(my GitHub count) and 'gpr.key'(my GitHub token) in gradle.properties（Project Properties）-> rebuild -> run ->logical build error ,see the pic:

[hewigovens]

1. Check your internet, you might need VPN or proxy
2. Check if your GitHub token has package reading permission