thanks. it didnt worked well but i'll try again

Hi. I have this board and in don't understand where the GND is. I can see only one, but I am not sure that I can use it for my parts.

Hi i have a problem i don't understand : i have a esp32 connected to ubidots. It send and receive data using mqtt. When i connect the esp to the pc or power bank every thing works perfect. But when i connect it to external power supply vue the vin pin it doesn't connect to the server. I knoe the pow...