Failed to import `svelt-yjs`

[KiddoV]

import { readableArray } from 'svelt-yjs';

Got error:

'readableArray' is declared but its value is never read.ts(6133)
Could not find a declaration file for module 'svelt-yjs'. '.../frontend/node_modules/svelt-yjs/build/src/main.js' implicitly has an 'any' type.
  Try `npm i --save-dev @types/svelt-yjs` if it exists or add a new declaration (.d.ts) file containing `declare module 'svelt-yjs';`ts(7016)