How to connect esp32devkit c to mdash to send data

Im new in mdash and this kind of things. I was trying to follow the documentation for mongoose and mdash to connect an esp32 devkit c to mdash without success. I achieved that mdash console show me “green” my device but I can not make my device save data to de DB.
Im using “mos” to flash de device but I read that I need a certificate, can someone be so kindly to show me an example in JS abot how to send data to de server and save it. Thank you.