stash/extension/options.js

const serverUrlEl = document.getElementById('serverUrl');
const tokenEl = document.getElementById('token');
const statusEl = document.getElementById('status');

chrome.storage.local.get(['serverUrl', 'token']).then(({ serverUrl, token }) => {
  if (serverUrl) serverUrlEl.value = serverUrl;
  if (token) tokenEl.value = token;
});

document.getElementById('save').addEventListener('click', async () => {
  await chrome.storage.local.set({
    serverUrl: serverUrlEl.value.trim(),
    token: tokenEl.value.trim(),
  });
  statusEl.textContent = 'Saved.';
  setTimeout(() => { statusEl.textContent = ''; }, 2000);
});