Synchronized video playback for remote clients

I was just looking at frame.io and found out that they have a feature to let the client see your video with a synchronized playhead - so you can see everything simultaneously. We often have the requirement in news to read the script in real time remotely while playing back the video so we can work on the text together before we record the overvoice. 
It would be easier for me to upload a video and play it back in sync than use a capture card to send the video output to a client via teams or zoom, but its not available for FCPx. Does anyone know a similar service where you can upload a video an play it back simultaneously with your client?
There are a lot of services for binge watching Netflix and amazon prime.. but none of them seems to have a function to upload you own videos - one of them uses google drive - but they say it takes hours for the video to become available. On the other hand there is the software syncplay which allows simultaneous playback of a local video via an app - but its too complicated to explain to a client - they only have a few minutes for reviewing a news piece and don't want to install any software and log into a server..
Any recommendations?