You need to install types for libraries you install. generally you should do:

npm install @types/libName // e.g. npm install @types/react-leaflet

Some times there's no types available in DefinitelyTyped repo and you encounter npm ERR! 404 Not Found: @types/my-untyped-module@latest. You can do several things in this occasion:

1- Create a decs.d.ts file in root of your project and write in it:

    declare module "libName" // e.g declare module 'react-leaflet'

2- Or simply suppress the error using @ts-ignore:

// @ts-ignore  
import Map from 'react-leaflet'

3- Or you can do yourself and others a favor and add the library types in DefinitelyTyped repo.

If it still doesn't work, I firstly recommend that you use a recent version of Typescript. if you do, then close your editor, delete node_modules folder and install the dependencies again (npm install or yarn install) and check it again.

I had the same error message, also related to the imports.

In my case, the problem was caused by importing a png file in order to use it in an SVG:

import logo from 'url:../../public/img/logo.png';

The message I received was:

Cannot find module 'url:../..public/img/logo.png' or its corresponding type declarations.

Solution:

In project root is a file css.d.ts. One must declare a module for the various graphics extensions (types) that are imported. (Note: Not for graphics types that are used or referenced in the project, but for those that are imported )

Here is the complete css.d.ts file for this project:

declare module '*.scss' {
  const css: { [key: string]: string };
  export default css;
}
declare module '*.sass' {
  const css: { [key: string]: string };
  export default css;
}
declare module 'react-markup';
declare module '*.webp';
declare module '*.png';
declare module '*.jpg';
declare module '*.jpeg';

I fixed my issue

1. create file /types/css.d.ts
2. open tsconfig.json

add this object:

"include": [
    "src",
    "types"
]

Check the dependencies object in package.json file. If the install package is in the format "@somepackage/packagename":version; then at the time of import you must use import abc from "@somepackage/packagename"

If "@somepackage/" is not there then don't use it at the time of import. Just simply use import abc from "packagename";

In my case I had my file named index.tsx whereas it should have been with capital I, so Index.tsx.

my situation:

myFolder is under the src dir

I see the same error in this line:

import { GlobalStyle } from "myFolder";

other answers dont work.

I simply add baseUrl to tsconfig.json inside compilerOptions:

{
  "compilerOptions": {
    "baseUrl": "src/",
//other config...
  },
  "include": [
    "src"
  ]
}

issue solved!

ref: https://www.typescriptlang.org/tsconfig#baseUrl

yarn2,3 has error for it.

you need to use yarn 1.22.1 version for it.

1. uninstall yarn

2. install yarn.

3. yarn set version 1.22.1

4. yarn policies set-version 1.22.1