The gamma_air is here the ID, it must be changed, there is second place below where you should change it too. The ID must be used while adding widget as Key
When you will be zipping the widget, zip them without any folder.
Attached example working widget to import. The KEY is alarm_fire_alert3
19.09.2020, 09:47 (This post was last modified: 19.09.2020, 09:51 by buuuudzik.)
I've checked this and yes, the unnecessary folder was a problem. Now I have teoretically my widget is on Extension list but only until I not refresh Mosaic.
Another thing is that this is probably not finished version of widget, under development, so it can probably have some bugs but I don't know how to create dev environment of Mosaic widgets so I am testing importing it into Mosaic.
But widget after import is not visible in available widgets to add and there is no feedback why. Also Mosaic after import widget hasn't bottom bar, but in console there is no error.
I've found that the problem was a lack of ";" after widget which was before my widget. A lot of widgets are created in IFFE and then all of them are concatenated so every widget should ends with ";".