By default, Blynk.Edgent library tries to use TLS (v1.2) connection between the hardware and server. This is true for the popular hardware like ESP32, ESP8266, NodeMCU, MKR 1000, etc. However, some boards don't support TLS, in that case plain (non encrypted) connection is used. You can check that in the serial console output of your board. Typical TLS connection port would be 443. For the plain connections port 80 is used.