Detail documentation is available at https://lakshay-anand.github.io/chromoMap/docs.html
If you want to count all 'N' in miltifasta file.
(base) ? output_2_test git:(master) ? more scaffolds.fasta | grep -Ho N * | uniq -c
12 draft_summary.info:N
1035948 scaffolds.fasta:N
12 scaffolds_summary.info:N
900 updatedGenome.fa:N