There are 2 ways you can add external URLs to your posts:
Click + Create, then click URL as the post type
Click + Create, then click Text as the post type, then under Media click URL
When you add the external link, an embedded image of the linked page will show up in your post. Along with the embedded image you can include any typed text in the "Title" and "Write your post..." fields.
Wondering how to add GIFs from online sources to posts?
Spaces now supports uploading animated GIF files, either directly from your device, or by embedding a URL from an online database (e.g. Giphy).
GIFs saved on your computer or mobile can be uploaded using the standard 'File' posting option. To post from a GIF URL:
Click + Create
Select URL as the post type
Include the link to your GIF in the URL field
(If you're a teacher) Select the students you want to post to
Wondering how to include GIFs in post comments?
Click the URL icon in the comment box
Enter the GIF URL
Click the blue check-mark (top right)
Note: GIFs cannot be added by directly pasting the GIF link in the Post text field or the comment box. This will only post the URL text without the hyperlink.