history.deleteUrl()

let deletingUrl = browser.history.deleteUrl(
  details         // object
)

let urlToRemove = "https://example.org/";

function onGot(results) {
  if (!results.length) {
    console.log(`${urlToRemove} was removed`);
  } else {
    console.log(`${urlToRemove} was not removed`);
  }
}

function onRemoved() {
  let searching = browser.history.search({
    text: urlToRemove,
    startTime: 0,
  });

  searching.then(onGot);
}

let deletingUrl = browser.history.deleteUrl({ url: urlToRemove });

deletingUrl.then(onRemoved);

function onRemoved(removeInfo) {
  if (removeInfo.urls.length) {
    console.log(`Removed: ${removeInfo.urls[0]}`);
  }
}

browser.history.onVisitRemoved.addListener(onRemoved);

function onGot(results) {
  if (results.length) {
    console.log(`Removing: ${results[0].url}`);
    browser.history.deleteUrl({ url: results[0].url });
  }
}

let searching = browser.history.search({
  text: "",
  startTime: 0,
  maxResults: 1,
});

searching.then(onGot);