Hello Albert Yang,
I hope this is the correct place to contact you about this. I'm encountering a bug in the code you posted. I'm running:

Matlab R2021a Update 1 (9.10.0.1649659)
64-bit (maci64)

load ecosystem_data.mat
plot_pairedimfs(time_DIDIPARA,DIDI,PARA,0.35,1000,[]);
causal_matrix = causal_decomposition(DIDI,PARA,0.35,1000)

test_causal_decomposition
Error using signalwavelet.internal.emd.emdOptions/parseInputsMatlab (line 52)
Expected a string scalar or character vector for the parameter name.

Error in signalwavelet.internal.emd.emdOptions (line 28)
this = this.parseInputsMatlab(varargin{:});

Error in emd>parseAndValidateInputs (line 203)
opt = signalwavelet.internal.emd.emdOptions(varargin{:});

Error in emd (line 134)
[x,t,td,isTT,opt] = parseAndValidateInputs(x, varargin{:});

Error in eemd (line 98)
imf = emd(xend, toModifyBC, typeSpline, numImf, maxSift);

Error in causal_decomposition (line 40)
imfs1=eemd(s1,rnoise,nensemble,0)';

Error in test_causal_decomposition (line 10)
causal_matrix = causal_decomposition(DIDI,PARA,0.35,1000)