I am not the best at JavaScript or NodeJS so I can't really give exact good, but just what I think is good advice.

If you want to implement this animation with just NodeJS, make sure you are using HTML and you have some libraries for animation (I'm sure you're probably already past this part) and make sure you have your libraries imported (I don't really understand how Node works, so I am just going by Python logic)

Now for the actual animation process, there's probably some sort of function to create lines in the canvas library. So, you can create your own function (Maybe name it something like "brushStroke()") and define it with some canvas functions to make it operate correctly.

Since the function for making lines probably requires the developer to state the coordinates for each plot connecting the lines, you should make sure that you find coordinates that make sense for the stroke, and so that it creates lines.

To make the lines look more like a brush stroke, you could also consider making the lines a bit thicker so it looks more natural.

If you want an actual animation for the stroke, try using a function that erases bits of each line from left to right in order. I don't really know how to explain this part, but the way the animation works is all up to you, since this is your project!

That's basically it! After the animation is done, you might want to reposition it or resize it. However, on't forget that I don't actually know that much about NodeJS, so everything I said was just about how to implement it and not how to code it.

I hoped this helped, and I hope you have a great rest of your day!