If the Autoredirect 404 setting is turned on (green), the plugin will start automatically redirecting most of the 404 pages.
In a case of a typo in the URL of the page, WP 301 Redirects will be able to find an existing page on your site that's very similar to the current URL. So instead of showing an error message, the plugin will redirect visitors to that similar page instead.
How does this work?
For example, you can make a mistake and go to https://yourdomain.com/example-pos where you forget to write the last letter "t". Usually, WordPress will show you a 404 error showing that the post doesn't exist. Instead of that, the WP 301 Redirects plugin would realize that there's an existing https://yourdomain.com/example-post page, and will automatically redirect you there.
In case there are more than one similar URLs found on the site, the plugin will find the page that's alphabetically the closest to the mistyped URL.
Post types used when auto redirecting
When the auto redirecting is turned on, you can decide what post types will be affected by this. By default, your posts & pages will be automatically redirected when possible, but you can choose to include any other post type to the rules.
To select more than one post type, hold down the control key on Windows, or command key on Mac, to select multiple post types.
Don't forget to save changes.