JavaScript files generated next to TypeScript files - how do I stop that?

Hi!

I'm working on an Angular project, and IntelliJ constantly generates js files right next to my ts files. But not for all of them. I haven't really found a pattern when it happens - but it is very annoying. How do I make it stop?

In angular.json, the projects.myApp.architects.build.options.outputPath ist "dist/apps/myApp" and in my tsconfig files the compilerOptions.outDir is "dist/out-tsc".

What might be responsible for the JS files being created in my src folder, right next to my TypeScript files?

I was thinking maybe the TypeScript language service, but it doesn't seem to have any compiler output related settings in Preferences | Languages & Frameworks | TypeScript...

How do I stop the generated source files being placed in the wrong folder?