Once your video is finished, you can share it directly to your Facebook timeline, Facebook page (with the Premium, Professional and Business plans) and even to your Facebook Ads Manager (with the Business plan).
To share your video on Facebook:
1) Click on the Share button 
2) Select Facebook
3) Select whether you want to post it on your Timeline, on a Facebook Page or to your Facebook Ads Manager
3/a) When sharing to Your Timeline*, you will be prompted with the Share on Facebook Screen:
You can “Say something about this..”, tag your friends, check in and control the privacy of the post (Facebook sharing features).
You can also toggle between sharing to your News feed and Your Story.
*Facebook recently changed the way apps can share videos directly into the timeline/profile, and from now on we can only share links to the Magisto player. This is a platform change on Facebook - a new policy for sharing.
You still get a post with a video in it, just not autoplaying (and not on FB).
Note that you can still use native share (share videos and not just links) when sharing to a FB Page.
3/b) When sharing to A Page you Manage (Premium, Professional and Business plan only), you will be prompted with the following screen:
If you have several pages - you can select the page you wish to share your video to. You can add a title and post text with your video.
Keep in mind because of the way Facebook permissions work, in order to share your video to a Facebook account or a Facebook page, you'll need to connect your personal Facebook account that has Admin rights to the Page you’re sharing to.
3/c) When sharing to your Facebook Ad Manager (Business plan only), you will be prompted with the following screen:
If you have several Facebook Ad accounts - select the relevant one, add a title to your video upload the video for further actions on Facebook.