By default, a published page can be accessed with an URL containing the unique ID for the page. However, you can change the page slug if you want the page to have a custom URL to which it can be accessed.
To change the page slug you will need to click an area outside the page to access the page settings.
Then enter the desired slug in the slug field. This field will automatically be converted to match the required format for a slug.
Click Save to save the changes to the page. You will get a warning if a page with a slug already exists on your team. In that case, try a new slug and save again.
Click on Options in the bottom-right and select View published to open a new window to the published page with the new custom URL.