How to use the nightwatch-api.client.url function in nightwatch-api

Given(/^I open the Seedpicker calculator$/, async () => {
    const workingDir = process.cwd()
    const fileUrl = "file://" + workingDir + "/calculator/last-word.html"
    await browser
        .url(fileUrl)
        .waitForElementVisible('body', 1000)
});
Then(/^I see the Seedpicker page$/, async function () {

Given(/^I open Google`s search page$/, async () => {
  await client.url('http://google.com');
});

Given(/^I open the Dice randomizer$/, async () => {
    const workingDir = process.cwd()
    const fileUrl = "file://" + workingDir + "/calculator/dice.html"
    await browser
        .url(fileUrl)
        .waitForElementVisible('body', 1000)
});
Given(/^I enter (\d+) in dice number (\d+)$/, async (dieValue, diceNo) => {

Given(/^I open DuckDuckGo search page$/, async () => {
  await client.url('https://duckduckgo.com/');
});