Serial communication with NODEMCU (esp8266) with Micro-controller

I am working on IOT. I have a mobile app that send data to NodeMCU . but i have to send this data to micro-controller. can you tell me how this is possble. actually i have worked with micro-controller . so i am not good with arduino. can you please tell me the proces , how can it will work. or what are the process to me to follow . ?

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