First of all, I'm shocked that this site posted the challenge to create a beam saber diorama in the diorama category after this article.
https://www.gn-app.com/posts/c925c9bf-6e16-46a1-abce-a940d8abc936
And the contest submissions didn't have glowing beam sabers. I was shocked twice.
First of all, you can make beam sabers glow using AI generation for free with a smartphone. The contest guidelines don't say you have to use anything other than the diorama tool. Plus, the editing process is so simple it's almost dead easy (

Honestly, I couldn't believe my eyes. | 名も無きアレ's Gunpla works