If the recorder video is in its final production stage, created with obs or with something else, I will suggest to use Facebook Premier feature.
Why?
If you use OBS you will experience the same stress and potential risks when live streaming, and you dont need that if the video is already recorded.
With Facebook Premiere your bandwidth or network limitations will only affect your upload time and if something happens you just restart the process.
The good thing about Premiere, even that it feels like just upoloading a video the normal way, is that it will trigger all the features of Facebook Live, like notify all subscribers that there is a Live Video now, and also, the experience, as a viewer in general, is the same as when you are watching a live stream.
Now, if the case is that you just have prerecorded scenes but you need to add things like lower thirds, transitions, effects and so, then you can either record the final product in OBS and them upload it using Premiere feature, or you can use OBS to live stream the whole thing using the prerecorded scenes as camera/video sources and you will be able to add texts, graphics and effects during the transmition like when you live stream for real.
