How can I use a REGLINX.ETS.IP.MULT function?

I dont have it at my LibO
When I write =reglinx… i dont have to choose this function? Should I instal any patch?

It might had helped if you specified what UI language you are using… I found REGLINX.ETS.IP.MULT() in the Polish translation, in an English UI it is FORECAST.ETS.PI.MULT()