Hi Luis,
For your previous post, you currently cannot insert CUDA or OpenCL into javascript files. The only GPU interface from JS that exists is WebGL (and the up-and-coming WebGPU standard).
If you want to do server-side rendering, check out ParaViewWeb. With ParaViewWeb, you have the option to drive vtk.js visualizations with a backend server. @Sebastien_Jourdain can tell you more about it.