[Sequencer] How to keyframe material emission ?

Using 4.21.2

I have an actor on a track that shoots ray at a certain time. I already add the FX, added a light but I need to change the light emission of the body. I already have the assigned emission map and I want it to fade in a certain frame from no-emission to full emission.

How can i do it ?
Any help is very welcome
Thx in advance

I found this… testing