FlugalTheWanderer, the OP posted a link to their (as of then) mainsite page, the source text of which is accessible via the "+ Options" link to the bottom right of the page. They used the standard rating module.
If the Upvote buttons have no visible wikidot code then this is likely a wikidot issue.
Rating module coding can be found on every SCP article on the site, as well as the How to Write an SCP Guide; "upvote" and "downvote" buttons are inherently built into the module coding (it would be silly if people could only upvote or only downvote), which in itself is rather simple. Please refrain from giving feedback in the help forums if you're unfamiliar with how standard template coding works.
ETA: Also, I'm fairly certain that the issue was resolved three days ago, anyway.