postman으로 raw 데이터를 전송하면 오류가 발생합니다.

오류내용 :

(node:992) UnhandledPromiseRejectionWarning: Error: 3 INVALID_ARGUMENT: Input text not set.       

    at Object.exports.createStatusError (/mnt/e/Projects/CB2/node_modules/grpc/src/common.js:91:15)

    at Object.onReceiveStatus (/mnt/e/Projects/CB2/node_modules/grpc/src/client_interceptors.js:1204:28)

    at InterceptingListener._callNext (/mnt/e/Projects/CB2/node_modules/grpc/src/client_interceptors.js:568:42)

    at InterceptingListener.onReceiveStatus (/mnt/e/Projects/CB2/node_modules/grpc/src/client_interceptors.js:618:8)

    at callback (/mnt/e/Projects/CB2/node_modules/grpc/src/client_interceptors.js:845:24)

(node:992) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)

(node:992) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

//////////////////////////////////////////////////////////////

raw 데이터로 

{

    "text":"hello!"

}

라고 강의대로 넣었습니다. Credential 문제도 해결했구요

뭐가 문제일까요?