Expected BEGIN_OBJECT but was STRING at line 1 column 177 code example
Example: expected begin_object but was string
Even without seeing your JSON string you can tell from the error message that it is not the correct structure to be parsed into an instance of your class.
Gson is expecting your JSON string to begin with an object opening brace. e.g.
{
But the string you have passed to it starts with an open quotes
"