Format container not showing .mov, .mp4 or even .mkv as a choice

[momokururin]

I've been trying to record a clip with Alpha Channel for several days now and I do need to change my format container to either .mov or .mkv from Settings>Output>Advanced>Custom Output (FFmpeg), but no video file format is showing up aside of a64 so far and I'm honestly lost.

I'm using the newest OBS version (30.0.0.2), but I also tried an old portable one out of desperation, to unfortunately no avail.
I already searched for topics on the matter on the forum but found nothing helpful for my case.
Can anyone help please? I've ffdshow installed so I should have all of the codecs already (OBS does export as those formats in simple mode, but I need to select a very specific codec and it can only be done in Advanced>Custom Output (FFmpeg))

Log file is attached here (it shouldn't be necessary as OBS isn't really crashing or anything but I thought it might help)

 

[R1CH]

Use the scroll bar in the list.

 

[momokururin]

Use the scroll bar in the list.

Omg I'm feeling so dumb thank you
My brightness is so low I didn't see the scrollbar at all

 

[Suslik V]

Scrollbar not visible - it is by theme design. System one shows both: groove and handle (not only handle). If you are new to OBS then it is wise to select System UI theme (than the default one).