They've actually changed how this works.
If you have some "impact" on the site (questions or answers) but zero flags at all or if you have zero handled flags or zero validated flags (all declined/disputed), you will see a link to the flag summary page, so while you can enter it manually, you don't need to any longer.
If you don't have any impact on the site, however, you will see an explanation of impact and you will still need the link. This is true even if you do have flags that were declined. Subsequent attempts to flag after having a flag declined will cause a popup with a link to the page directly, so that's helpful.
As few as one "Helpful" flag on a site with zero impact, however, will cause the link to appear.
Which means that in most cases, you should be able to see this link.
This was actually addressed in a feature request which is now status-completed. If I have flagged a post, show me a "flags" link in my profile