{"NAME":"ESP12F_Relay_X16","GPIO":[1,1,1,1,1,7712,1,1,7680,7648,7744,1,1,1],"FLAG":0,"BASE":18}

This device uses two 74HC595 serial registers to control the relays, which are not enabled in default builds. Therefore you need to compile your own Tasmota binary, enabling USE_SHIFT595 setting.

After configuring the template you need to go to the console and run Shift595DeviceCount 2 command to setup shift registers. After that the device will reboot and all 16 relays will be visible in WebUI.

IMPORTANT! Currently only the first 8 relays are available in autodiscovery MQTT topics.