post static method
Implementation
static Future<String?> post({required String api, required Map<String, String> params}) async{
try{
Response response = await dio.post(api, queryParameters: params);
if(response.statusCode == 200 || response.statusCode == 201) return jsonEncode(response.data);
return null;
} on DioError catch(e) {
return null;
}
}