React Hook "useLocation" is called in function "fetchGuests" that is neither a React function component nor a custom React Hook function. React component names must start with an uppercase letter react-hooks/rules-of-hooks code example

Example 1: React Hook "React.useState" is called in function "placeItem" which is neither a React function component or a custom React Hook function react-hooks/rules-of-hooks

React Hook "React.useState" is called in function "placeItem" which is neither a React function component or a custom React Hook function  react-hooks/rules-of-hooks

answer :- function name must be start with capital letter

Example 2: React Hook "useState" is called in function "app" which is neither a React function component or a custom React Hook function react-hooks/rules-of-hooks

capitalize 
const App