White Hat
White Hat SEO: How to Rank Without Breaking the Rules by WordStream...white hat SEO refers to any practice that improves your search rankings on a search engine results page (SERP) while maintaining the integrity of your website and staying within the search engines' terms of service. These tactics stay within the bounds as defined by Google...
If you are interested in the other hats of SEO here is an article on Search Engine Journal you can read: SEO Tactics: Black Hats, White Hats, Gray Hats & ‘Asshats’ (make sure you don't do anything "Asshat" or hire someone that uses "Asshat" techniques.
So onto the white hat techniques described in this article on HubSpot: 11 Creative (But 100% White Hat!) Ways to Earn Backlinks in 2020
Have you tried the methods mentioned in the article yourself? If so, explain how it worked out for you below.