I must not have made myself clear. Apologies. I'm trying to shoot Facebook Live stream. There is no option to do that in Facebook-via-browser, it only makes itself available in the app itself. And, you need to be able to flip that Facebook app to landscape in order to properly shoot/broadcast Live in landscape mode. Elsewise, your video ends up either vertical (with black/gray fields on either side) or sideways. MAJOR drag to not be able to do this with an iPhone. Anyone with a Samsung or some such Android-type device can do it every day, no problem. However, I have just found the iPhone work-around, if anyone happens to be interested. Maybe you might be, since I've not been able to find anyone anywhere on the web who knows this...
iPhone Work-Around: Facebook Live in Landscape Mode
It was very frustrating for me to discover that, while attempting to shoot a live Facebook video broadcast, the Facebook app would not rotate to landscape orientation when flipping my iPhone 8 to horizontal. This problem renders the user with a portrait (or vertical) video only - or worse: sideways! But, by accident, I stumbled upon a work-around. For some inexplicable reason, landscape mode works perfectly as it should while shooting in “selfie” mode. No idea why. Of course, you don’t want to be shooting in selfie, ‘cause the selfie camera is inferior. But, the discovery led me to the fix. I sincerely hope this helps others with this annoying roadblock…
1.) Hold the iPhone vertically in your hand.
2.) Open the Facebook app.
3.) Keeping the phone vertical, tap the “Live”
icon.
4.) Remaining vertical, tap the “selfie”
icon.
5.) Rotate phone to horizontal (you'll see your selfie rotate).
6.) Tap the “selfie” icon again to switch camera to outward orientation.
7.) When you’re ready to start broadcasting, tap the blue “Start Live Video”
button to begin recording live stream in landscape mode.
When you get the camera in view, you can tap the “To:” and choose “Only Me” for who can see your video. Then you can make private tests to see if I’m totally crazy... which I do not believe I am.