To send a single post to approval, simply clicking the To Approval button in the post editor when in post edit mode will send it away. You also have two more ways to send multiple content to approval from the main content calendar of your brand or all posts view.
These two views allow you to send all content from every channel you manage for a single client at once.
Inside the calendar you can filter content by status, channel, formats, and tags to find specific content easily and send it all to approval at once.
To send to approval select all that apply in the calendar and then click the To Approval button. Make sure to select posts with the same status, otherwise, you will not be able to send them to approval.
Depending on what you're trying to accomplish, the list view might serve better to send content to approval in bulk. You can check up posts for a final overview before sending them to approval, just as in the calendar you can filter by status, tags, formats, channels, and specific dates.