issues with making a matlab firfilter

I am trying to write a matlab code to design a firfilter but I am having trouble getting the filter to work this code below is supposed to determine the frequencies and filter them out of the sunshinesquare.wav file. however when I go to run the program matlab tells me there is an error with the notchfilter line but I can't figure out what is wrong with it any suggestions/help is greatly appreciated.

My code is below

[x, fs] = audioread('SunshineSquare.wav'); 
 
X = fft(x); 
f = linspace(0, fs/2, length(X)/2);
[~, f0] = max(abs(X(1:length(X)/2))); 
 
notchFilter = fdesign.notch('N,Fc', 100, f0, fs); 
b = firpm(notchFilter); 

 
y = filter(b, 1, x); 


sound(x, fs);

Answer 1

[Chunru]

%[x, fs] = audioread('SunshineSquare.wav'); 
load handel.mat
audiowrite("handel.wav", y, Fs);


[x, fs] = audioread('handel.wav'); 
 
X = fft(x); 

f = linspace(0, fs/2, length(X)/2);
[~, f0] = max(abs(X(1:length(X)/2))); 

Warning: Integer operands are required for colon operator when used as index.

f = (f0-1)/fs;          % the corresponding freq for index f0 
notchFilter_spec = fdesign.notch('N,F0,Q', 100, f, 10, fs/2);    % 

notchFilter = design(notchFilter_spec, 'Systemobject', true)

notchFilter = 
  dsp.SOSFilter with properties:

            Structure: 'Direct form II'
    CoefficientSource: 'Property'
            Numerator: [50×3 double]
          Denominator: [50×3 double]
       HasScaleValues: true
          ScaleValues: [1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 … ] (1×51 double)

  Use get to show all properties

% fvtool(notchFilter)
y = notchFilter(x);
 
%y = filter(b, 1, x); 
% sound(x, fs);
subplot(211); plot(x);
subplot(212); plot(y)