If I want to introduce the js plug-in I downloaded, how should I write the declaration file?

[simpleET]

If I want to introduce the js plug-in I downloaded, how should I write the declaration file?
just like this:
import scrollJs from '../plug/scrollJs.js'

[DanielRosenwasser]

Probably a better fit for StackOverflow, but you'd create a scrollJs.d.ts file that describes the exports if you're willing to place the files there.