turning a dynamic animation into a gif

I wanted to create an animation with a firework and export that as gif (as preview) and js/canvas animation.

A firework has a lot of moving parts, so I thought I'd simply use a script to, for example, take twenty elements from the library, place them on the stage, and move them into different directions.

I hoped that when I'd export that into a gif, Adobe Animate would basically take what it sees in the preview window and turn that into a gif. However, it seems that Animate ignores all scripts when exporting as a gif. I assume that this is just the way it is? The only solution I see here is to export the animation as a flash animation, record that as a video, turn that video into a gif animation. But is there no better way?

Thank you