How to multiply two FFTs in MATLAB?
You have two signals of length $N = 220500$ and $ L =  8821$ samples long, and you want to obtain their convolution $y[n]$ of length $K = N + L-1 = 229320$ samples long, by using a frequency-domain DFT//FFT method...
Then you have to compute $K = N + L -1 = 229320$ sample long FFTs of both signals $x[n]$ and $h[n]$, and then multiply them, and then invert the resulting spectrum back into time-domain as given by the following MATLAB line.
% assuming x[n] and h[n] exist....
N = 220500;  % length of x[n]
L = 8821;    % length of impulse response h[n]
K = N+ K -1; % length of output y[n] = x[n] * h[n]

y = real( ifft( fft(x,K).*fft(h,K) , K ); % y[n]: