ESP8266 and google sheets data transfer in real time

I need a custom program developed for real-time bi-directional transferring and receiving data and controlling aspects between my ESP8266 setup and Google Sheets in real-time. The data to be transferred between them includes things like temperature and humidity readings, sensor readings from multiple sensors, and custom data fields. I already have an existing ESP8266 setup and Google Sheets integration set up, so I just need the custom program to facilitate the transfer and reception of data between these two platforms. The data needs to be transferred in real-time. Also, without using any third part service /platform or any midlleware between them. Maximum acceptable delay between sending and receiving data should be less than 1 seconds. Also it should be scalable and secure. For programming ESP8266 we are using Arduino ide and AppScripts for Google sheets.