For example, here we dragged the Wifi Setup block into the BLOX Block's Initialization field:

Customize the settings according to your network.

When the device boots up with the firmware, it will connect to the configured Wifi network during the Initialization process

For example, here we dragged the If Wifi is Connected block into the BLOX Block's Run field:

In this example we're using it to track the status of the Wifi connection, and change the onboard LEDs on the BLOX to indicate the connection status