You will have to change the privacy of your posts to make them shareable. Posts set to public can be shared by everyone.
First, navigate to the post you want to make shareable. Click the three dots symbol in the upper right corner of that post. You’ll then see options to pin it, edit it, archive it, and so on. Select the option in the middle that says “Edit Privacy.”
Facebook Help Team
If the privacy setting of your post is set to “Public,” anyone can share it.
Facebook is removing the share option for everyone. It is being rolled out slowly. Despite setting it to public, it will not appear anymore.
If you want to make a previous post shareable, after locating the post, select the ellipsis icon (•••) on the right side of the post and choose “Edit Post.” Select the first drop-down menu below your name (labeled “Friends”) and choose “Public” on the new page.
Why is there no public option on Facebook?
Facebook Help Team
Hi Salal, If you’re under 18, you won’t be able to post to “Public.” The maximum audience you can share with is friends of friends.
How do I make my Facebook post public?
This is the arrow in the upper right corner of the post. Tap Edit Privacy. Tap Public. The post is now visible to anyone, whether or not they have a Facebook account or are friends with your on Facebook.
If you don’t want your photo, post or other content to be visible to the friends of the person tagged, you can turn this setting off for each post when you post it. To do this, click the audience selector next to the story, select Custom, and uncheck the Friends of those tagged box.
Only the people who could see those posts when you first made them are able to see them when someone taps Share. Use the audience selector to adjust who you share posts with. Note: When a friend shares a link that you posted, they can share the link with a wider audience than you originally shared it with.
If a post has been shared, it’ll tell you the name of the person and how many hours ago they shared it. You may also receive an email informing you of this, depending on if you have email updates set up.