My .kv file is not supported by VScode. VScode suggested two extensions to work with .kv files which are Kivy and KVlang. I installed them both but I still get an error: Kivy files require #:kivy !ex.
You need to declare #:kivy 1.x at the top of your .kv file. Replace the 1.x with whatver version you are using for example I am using 2.0 so mine looks like #:kivy 2.0
.kv file is not supported