Scroll down the page to Maintenance page options section and configure provided options.
You can also enter plain text in default Wordpress editor.
When you are ready, save the page and view it. You can see demo Maintenance mode page here.
Maintenance mode page is an alternative to Coming soon page. There is special template for such page and predefined options. Create a new page in Pages>Add new and choose Maintenance mode template in Page Attributes section.
Scroll down the page to Maintenance page options section and configure provided options.
You can also enter plain text in default Wordpress editor.
When you are ready, save the page and view it. You can see demo Maintenance mode page here.