Is it any template based video format? Wants to create an animation video able to use for Facebook ads. Aim is to do direct marketing with videos, so video content is based on the target audience. The video is composition of a template, static background, and some photos that are moving in the video. Video needs to render for different advertisement with different photo set. Is it possible somehow? Is it a format i.e. I put template video and photos in one folder and when "starting" video, video "loads" photos in? Or I need to use an online / cloud based video editing tool which allows programmatic video edition?
As well as @ElderGeek's suggestion of ffmpeg, Adobe After effects can be used to generate bespoke video for the web. It can be fully scripted using Adobe's extendscript on the server and run as a headless process. You can thus programmatically create video templates and alter such things as text, image content, or insert clips, then render and deliver.
Note that the rendering does take time and CPU (for both ffmpeg and AE). To achieve real-time customisation you may want to consider using the HTML canvas element, which can support video and animation, working on the client side.