Particle Documentation - Particle Initial Spin component

Starts the particle with a specified orientation and rotation rate.

"minecraft:particle_initial_spin": {
    // specifies the initial rotation in degrees
    // evaluated once
    "rotation": <float/molang> <default:0>

    // specifies the spin rate in degrees/second
    // evaluated once
    "rotation_rate": <float/molang> <default:0>
}