Technical Issue: Cannot use particle cmd

I am on a Mac, using the Beta version.

I cannot get particle commands to appear.

I get a message saying all players have been sent something, but I see no animations.

1. Classroom consequence: It is nice to be able to have a particle animation on NPCs, so students know who to talk to.

2. I could be fouling up, but I have tried a new and older world with this command:

/particle minecraft:electric_spark_particle ~ ~ ~

Thanks~