indexing quickly

Do Some social share.

Google is slow these days. No matter what you do, they are not indexing some links for a few weeks. GSA spammy blast may take even longer to index. If it's just a few backlinks, you can get PBN links to index. They worked well for me. But, in your case, it's going to take long as regular social shares are out of discussion here.

As one person said above me I would recommend social signals. You can also try using a bot to share the links in Facebook groups that are public.