Render a data stream (HTML or raw) into a RTMP video feed

I am looking for a solution to render various micro sites (small html based widgets) server side into a video feed to be output to a streaming server. The output should be an RTMP stream. The data on these micro sites changes all the time so the realtime encoding of the site to video stream is very important. Please note that the rendering has to be done on a linux server without using any GUI based solutions. So tools like OBS are out of the question. The solution should also be able to render various sources into various streams on a single server, for example [login to view URL] https://localhost/[login to view URL] rtmp://localhost:1935/datastream/stream1 & [login to view URL] https://localhost/[login to view URL] rtmp://localhost:1935/datastream/stream2 & [login to view URL] https://localhost/[login to view URL] rtmp://localhost:1935/datastream/stream3 & I am looking forward to good solutions proposals. If you have a better solution to create nice looking video stream widgets, please feel free to propose. PLEASE NOTE: As I respect your time and mine, only proposals from partners who can show previous references of such a solution or can provide a free POC within 24h will be considered.