Created by: trainto
As react version is 17.0.1, @types/react and @types/react-dom should be updated too. Also, typescript version should be 4.1.2. (I'm not sure what causes this, but when I create typescript project with CRA 4.0.1, installed node_modules/typescript version is 4.1.2, but root package.json describes it as "^4.0.3".)