The extension finds React PropTypes and adds them to the suggestion list.
It works for all implementations of the "PropTypes" feature, i.e. static propTypes, proptypes from a prototype, etc.
If the extension doesn't work try to configure jsconfig.json.
Your imports have to be resolved to work with this extension:
{
"compilerOptions": {
"jsx": "react",
"baseUrl": "./src/js"
}
}"baseUrl" - base directory to resolve imports