Worth saying plainly: R7's extractor is currently flagged unreliable upstream because the site changed something and the fix has not landed yet. If the R7 link fails here, that is far more likely than the link being wrong. Everything that does resolve still comes back untouched. R7 is handled by the media route, which reads the site's own rendition list before choosing anything. The renditions we see from R7 arrive as MP4. No credentials are involved anywhere in this path — neither yours nor ours.
Either paste a R7 link above, or put tikt.com/ in front of any R7 URL in your address bar:
tikt.com/https://www.example.com/path/to/media
From the R7 link to a saved file
1. Copy the R7 link
Use the address bar or the platform's own share button — both give a URL the extractor recognises. Point it at the single item you want, not the page around it.
2. Let it read the renditions
Paste the URL above. The extractor asks R7 which renditions exist for that item and picks the best progressive one rather than assuming a quality.
3. Save what comes back
The file arrives in the container R7 served it in, and the extractor does not rebuild it — so what you end up with is what the uploader encoded, for better or worse.