How to make niagara VFX system work in animations? (UE 4.27)

I’m making an animation for AVI export using level sequencer.

I’ve placed lots of niagara VFX in my level but when I export an AVI they do not show in the final video.

screenshot here

I’ve tried controlling/activating a niagara VFX in the level sequencer to no avail. None of the tracks I’ve added seem to make a difference.

I tried event/trigger, autoactivate, FX stystem toggle track

adding niagaracomponent > system lifecycle set to ‘desired age’

screenshot here

Can anyone please help?

Cheers