Mitsubishi heat pump intergration


I am new to HA and Node red - worked in IT for 25+ years and am very impresses with HA so far. I do have a query and hope someone could shed some light please.

I have a Mitsubishi heap pump plus Growatt solar and batteries. Objective is to force heat pump to come on and heat the house and/or heat DHW on demand via node red. In particular i am wanting to do this when batteries are 100% and solar is over 1kw - the idea is that i can squeeze every last drop out of the solar.

I can currently read and edit my solar/battery settings using mqtt but as far as the Mitsubishi heat pump is concerned, i cannot see where I can press the boost heat button. I do have the Mitsubishi addon installed in HA and i can press the hot_water_now option in the water_heater.indoor_unit entity but i cannot for the life of me see how i can instruct this through Node red.

Any thoughts on this before I pull my hair out. Is there a way of using Node red to action a HA entity?

Many thanks for any replies.