URL restriction is only available for works submitted using the Requests feature.
It is available on both the desktop and mobile versions of pixiv.
Only people who know the URL can view the works posted as "URL restricted".
They will not be visible on your browsing history or profile page.
Also, unlike works that are posted normally, URL-restricted works have limited functions.
・The artist cannot add URL-restricted works to a manga series, start a poll, or use the Image Response feature.
・Third parties are not allowed to like, bookmark, comment on the work, or edit tags.
You can update this URL as many times as you like.
Please note that once you update the URL, the work will no longer be visible at the previous address.
If you change the privacy settings for your work to "Make public" after posting, the URL of a URL-restricted work will be redirected to the URL of the normal work details page.