Calling peaks with MACS following Bedtools

Question

[bioinformatics.girl]

I ran the following bedtools job commanding the following:

bedtools bamtobed -I bam_file.bam

Now, how do I get from this to calling peaks in MACS within Signac (I have generated a _summits.bed, peak_annotation.tsv, _peaks.xls, and .narrowPeak file). Please provide code as the tutorial is not clear enough for me.