Need help to connect Speeduino with Wemos Mega+Wifi R3 board

I want someone to help me with coding. This board is not able to connect to Tunerstudio for some reason i dont know. The problem is, this specific wemos mega2560+esp8266 board only communicate each other through Serial 3. my current understanding is the speeduino codes communicate through serial 0 or serial 1. i bugged ChatGPT a lot and i was not able to find a good solution for it. It asks me to change All Serial as Serial3. I dont have the proper knowledge to make it happen. i'm trying this for few weeks now, but still cant figure how to make it work. there are people who make ESP8266 communicate with Tunerstudio. But this board has built in esp8266 which only communicate through Serial 3 making things harder for me. please help me by guiding me on how to make it work. This could also help you because, this device fits nicely inside the box without the bluetooth modules and wires hanging around and has a better range of 50m. they say with a proper antenna it can extend upto 200m. Please help me