Diffbind Subsetting and Plot Consensus Peakset

Question

[pacman]

I am trying to plot PCA for the promoter-specific consensus peaks ( occupancy analysis) , but can't find a way to do it in DiffBind,

From this previous answer, I am able to get the promoter-specific consensus peak set but I have no idea how to compute the matrix from that peak set for the PCA :

peak.promoter <- dba.peakset(dba,bRetrieve=TRUE,
                             peaks=promoter.gr )
promoter.counts <- dba.count(dba,peaks=peaks)