Why the Butterworth filter is not working

I have the following code that I use to filter my data:

I have the following code that I use to filter my data:

freq1 = 60; % frequency of acquisition

n = 4; % filter order

freq_cut = 4; % cutoff frequency

Wn = freq_cut / (freq1 / 2);

[b, a] = butter (n, Wn); % defining Butterworth filter type

% Filtering data using FILTFILT

SMap = filtfilt (b, a, SAP);

But, for some reason, I can't use it in the 2019 version of matlab, and the following message appears:

Error using Untitled (line 60)

'butter' requires one of the following:

DSP System Toolbox

Signal Processing Toolbox

What can I do?

Thanks!

[Star Strider]

‘What can I do?’

License, download and install one of those Toolboxes. (My preference would be the Signal Processing Toolbox, however I do not know what you are doing, or which would be more appropriate in your situation.)