code: def post(self):
          
          if not request.is_json:
              return self.response_400(message="Request is not JSON")
          try:
              item = self.add_model_schema.load(request.json)
          except ValidationError as err:
              return self.response_422(message=err.messages)
          # This validates custom Schema with custom validations
          if isinstance(item.data, dict):
              return self.response_422(message=item.errors)
          self.pre_add(item.data)
          try:
              self.datamodel.add(item.data, raise_exception=True)
              self.post_add(item.data)
              return self.response(
                  201,
                  **{
                      API_RESULT_RES_KEY: self.add_model_schema.dump(
                          item.data, many=False
                      ).data,
                      "id": self.datamodel.get_pk_value(item.data),
                  }
              )
          except IntegrityError as e:
              return self.response_422(message=str(e.orig))
docs: POST item to Model
          ---
          post:
            requestBody:
              description: Model schema
              required: true
              content:
                application/json:
                  schema:
                    $ref: '#/components/schemas/{{self.__class__.__name__}}.post'
            responses:
              201:
                description: Item inserted
                content:
                  application/json:
                    schema:
                      type: object
                      properties:
                        id:
                          type: string
                        result:
                          $ref: '#/components/schemas/{{self.__class__.__name__}}.post'
              400:
                $ref: '#/components/responses/400'
              401:
                $ref: '#/components/responses/401'
              422:
                $ref: '#/components/responses/422'
              500:
                $ref: '#/components/responses/500'