When Amazon Echo does not connect to the Wi-Fi, you need to restart your echo and network hardware.
Ø To begin, turn off the router and modem for some few seconds.
Ø Now turn them back on and wait for them to restart.
Ø When the hardware restarts, unplug the power cord or adapter from the Echo device and wait for some seconds before plugging it back in.
If the problem still remains, you can amazon echo plus support phone number.
Click below for technical support:
amazon echo dot customer support phone number