Correct way to import CSS used by 3rd-party library?

I am building a SPA where the registration page will make use of the Leaflet mapping library. I have installed Leaflet by running the command

npm install leaflet

npm install leaflet

.

If I am only using Leaflet in the registration page, what is the correct way to import the Leaflet CSS file (

"leaflet/dist/leaflet.css"

"leaflet/dist/leaflet.css"

) and the Leaflet JS module?

Correct way to import CSS used by 3rd-party library? - SolidJS