High PR Web 2.0 Submitter
https://high-pr-blog-submitter.com/
High PR Bookmark Submitter
https://high-pr-social-bookmarking-software.com/
EDU/GOV Links Generator
https://www.apple-developers-inc.com/edu-backlink-software/
I found these software at GSA froum, seems it works for others.
Not sure how effiective these are, but maybe worth a try!