thats very hard to do for a custom widget that we dont know.
do you have a link to the custom widget?
did you copy the custom widget to the right place? with the right filerights?
do you get errors?
is there any kind of description?
leaving things empty after a : is most of the times a bad idea.
if its written correct then those lines are not needed.
first you need to create a working custom widget. (for instance by copying an existing one and modifying it.)
then you can start to change it.
you can compare the base_heater with base_switch files.
base_switch has only 1 entity, base_heater has 2 entities.
the problem is that a widget like that isnt that usefull in most cases.
you need at least the space from four widgets to make it workable (or else the toucharea would be to small)
so you could also use 4 widgets to do the trick.
Useful or not it depends)
For my setup heater is absolutely useless, but I’m not stating that it isn’t useful for others)
4 widgets can work but it’s ugly, same as having 4 widgets for the heater (temperature sensor, fan, minus and plus buttons for the temperature)
In my setup I want to use for example big button (2x2) to turn on/off the tv, and the small buttons/icons in the corners will control tv input (usually no need to change, only sometimes) so it will accessible but not taking too much extra space.
Still, the idea is one big “main” trigger (often use, common/standard scene) and several small (not often use, advanced entities). I started a repository, tried to put additional entity as I saw in baseheater, but no luck, the icon updating on both buttons: