What “it” is configurable? If the code is indented with 4 spaces, it is indented with 4 spaces. You can configure your editor to indent with 1 space if you want, but then your code is not going to respect the 4 spaces of indentation used by the rest of the code.

I repeat, the only accessible indentation option is using tabs. This is not an opinion because every other option forces extra painful steps for those with vision issues (including, but not limited to, having to reformat the source files to tabs so they can work on them and then reformat them back to using spaces in order to commit them)