java.lang.IllegalArgumentException: Could not locate RequestBody converter

Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(API_URL)
            .addConverterFactory(GsonConverterFactory.create())
            .build();

 

implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.squareup.retrofit2:retrofit:2.9.0'

原因：Retrofit庫不支持json序列化，需要添加converter庫