Tools, or the metadata panel in the editors. Two different jobs live here: taking things out, and putting things in.

Stripping before you post

Export → Strip All Metadata removes everything the camera or phone wrote.

That can include GPS coordinates, the device model, serial numbers and creation timestamps. A photograph or video straight off a phone often carries the location it was taken, and posting it publishes that location.

Strip by default on anything going out publicly. There is no cost to it.

Setting your own fields

The metadata editor carries the ordinary fields: title, artist, copyright and the rest. New tag key and New tag value with Add Tag handle anything that does not have its own box.

Clear All Fields empties them, and asks you to confirm.

When an export strips source metadata, your edited fields are written afterwards. So stripping and setting your own in the same pass does what you want rather than fighting each other.

A copyright line costs nothing and travels with the file wherever it goes.

Presets

New metadata preset name and Save Metadata Preset keep a set of fields you use often. Your standard copyright and artist line becomes one click instead of retyping it on every export.

Cover art

Video cover behavior decides how a cover image is attached.

Export Cover Frame makes one from the video itself, with Cover size, Cover frame format, and optional Cover frame text at Cover text size (pixels) over it.

First frame duration (seconds) holds the cover at the front of the file.

Remove Cover Art takes an existing one off, and asks you to confirm.

Pick the cover frame deliberately

On every platform the still does more work than the first ten seconds of the piece. Left alone, a platform usually grabs frame one, which is often black or a face mid blink.

Pick a frame where the subject is looking at the camera and the shot is well lit, and it will outperform anything the platform chooses.