code: def place_order(self, quantity, symbol, price):
          
          if price < 0:
              raise Exception("Price must be positive.")
  
          endpoint = "order"
          # Generate a unique clOrdID with our prefix so we can identify it.
          clOrdID = self.orderIDPrefix + base64.b64encode(uuid.uuid4().bytes).decode('ascii').rstrip('=\n')
          postdict = {
              'symbol': symbol,
              'quantity': quantity,
              'price': price,
              'clOrdID': clOrdID
          }
          return self._curl_bitmex(api=endpoint, postdict=postdict, verb="POST")
docs: Place an order.