get backlinks related to you niche and adopt a strategy and variation to build links and make sure to not build links on high spam score sites

Black hat SEO is a practice against search engine guidelines, used to get a site ranking higher in search results. These unethical tactics don't solve for the searcher and often end in a penalty from search engines. Black hat techniques include keyword stuffing, cloaking, and using private link networks

if you are talking about third part metrics domain authority then keep in mind that you just do not need to increase your domain authority of them they will show you 0 result. If you want to increase your domain authority organically then i would suggest you to go for guest posts, do guest posting of your website on daily basis.