For indexing, you can either use indexing services from the marketplace or build some tier 2 links pointing to your tier 1 backlinks and then submit those tier 2 links to an indexing service.
However, keep in mind that building more tier 2 links doesn't guarantee that your tier 1 links will get indexed.
Personally, I would start with 4-5 of relevant tier 2 links for each tier 1 link rather than creating dozens of links right away. If you're using an indexing service, test a small batch first and check the results before scaling up.
If you don't want to use indexing services, you can try building relevant tier 2 links and giving Google more ways to discover your tier 1 links.
Indexing has become trickier, but the goal shouldn't be to build as many links as possible just to get them indexed.
Focus on link quality, relevance, and natural discovery. Also, remember that getting a backlink indexed doesn't automatically mean it will pass value or improve your rankings.
Hope it helps .