I accidentally factory reset one of the plugs and the button stopped toggling the switch. This was the coffee machine – a slight catastrophe for the odd times it needed a manual toggle.
I found the athom page had a mystery “template” and worked out where to enter it on the tasmota. Job done.
{"NAME":"Athom Plug V2","GPIO":[0,0,0,3104,0,32,0,0,224,576,0,0,0,0],"FLAG":0,"BASE":18}
Configure Other, then put it in a the top and tick Activate.