@react-navigation/web/src/handleServerRequest.js

import { NavigationActions, getNavigation } from '@react-navigation/core';

export default function handleServerRequest(Router, pathWithLeadingSlash, query) {
  const path = pathWithLeadingSlash.slice(1);

  // Get initial action from the URL
  const navigationAction = Router.getActionForPathAndParams(path, query) || NavigationActions.init();

  // Get state from reducer
  const navigationState = Router.getStateForAction(navigationAction);
  // Prepare top-level navigation prop
  const actionSubscribers = new Set();
  const navigation = getNavigation(Router, navigationState, () => {}, actionSubscribers, () => ({}), () => navigation);
  // Get title from active screen options
  const activeKey = navigationState.routes[navigationState.index].key;
  const activeChildNavigation = navigation.getChildNavigation(activeKey);
  const options = Router.getScreenOptions(activeChildNavigation);
  const title = options.title || options.headerTitle;

  return { navigation, title };
}