How to disable expandtab feature?

[ProgrammingLife]

coc-rls enables it by default and overrides my noexpandtab option which set in .vimrc.
I have:

	"rls.insertSpaces": false,

in my :CocConfig file.
After manually call the command:

:set noexpandtab

all works as expected. But I already have set noexpandtab setting in my ~/.vimrc and it works fine for any other languages but not for Rust.

How to change this behaviour?

[Qiming zhao]

There's no such config "rls.insertSpaces"
'expandtab' option of buffer should be respected, check output of language server