React Hook "useRef" is called in function "header" that is neither a React function component nor a custom React Hook function. React component names must start with an uppercase letter. React Hook names must start with the word "use".Screenshot here

CodePudding user response：

This error message is pretty straightforward. If header is a React component, its name should start with a capital letter:

const Header = () => {
  // ...
}

CodePudding user response：

The shown error is not about useRef, you used it inside a wrong named react component header, should be named Header instead alway with an uppercase.