DAPARS2 generate region annotation output bed’s size is 0

hello everyone, I want to generate region annotation using dapars2, but the output bed file’s size is zero, the bed file from the test data provided by dapars2 is also zero, the same as my data’s .

Total extracted 3' UTR: 45180
sh: 1: subtractBed: not found

I don’t know how to resolve it, any guidance is appreciated!