hello
in terms of signal processing, a moving average filter is a FIR with all coefficients of the numerator equals ( = 1/n if the FIR numerator length = n , your average length)
use the "discrete filter" block
NB : you can design any FIR or IIR low pass filter , they will all do your average work with simply different cut off frequency and different slope , so this will both affect the transient and steady state error.
as alternative you can use a "buffer" block followed by the math function "mean"
see example attached
