To add packages from any NPM-compatible registry, a custom registry must be added in the extension settings (Custom Registries).
NPM-compatible registries only support search results based on search terms.
The following example adds the public npmjs.org registry, with a pre-configured search query for packages containing @ax and simatic-1500:
{
"siemens.apax-v3.registriesExplorer.customRegistries": [
{
"name": "npmjs.org",
"url": "https://registry.npmjs.org/",
"registry_type": "npm",
"searches":[
{
"search_terms": ["@ax", "simatic-1500"]
}
]
}
]
}