It looks like you're trying to use TypeScript but do not have the required package(s) installed.
Please install @types/react by running:
yarn add --dev @types/react
If you are not trying to use TypeScript, please remove the tsconfig.json file from your package root (and any TypeScript files in your pages directory).
버전 문제일 수 있다.
Next.js와 React 업데이트 ㄱㄱ
npm install next@latest
npm upgrade react@latest react-dom@latest
오 덕분에 해결했습니다 감사합니다!