In order to increase the domain authority, you need to build QUALITY backlinks to your site. Quality wins over quantity as far as backlinks are concerned. You have to make sure that every of your backlink should be of high quality. In order to increase the overall domain authority you need to build backlinks preferably to the internal pages of your blog. As the internal pages link back to the home page of your blog or site through header image or text, the authority flows automatically back to the homepage. So back linking to the internal pages works great in increasing domain authority. Increasing the number of referring root domains also helps in increasing domain authority. Backlinks that you're getting should be from diverse sites related to your niche. The backlinks that are from the unrelated sites do not count as a factor for Domain authority. At last, the important thing case you have to wait. All that matters while increasing domain authority is the age of the domain.
Get more high DA links to the site from high relevant sites and then share those on social media . Depending on the keywords you are trying to rank for, check what your competitor backlinks are and make yours better!! I have access to DA 60+ magazine sites if you are intersted. Also, can help with wikipedia as I am an established editor. Great content is all it takes
Your DA can only improve only if you get back links from higher authoritative websites with a good DA. For that you have to submit links to them engage with those sites. Once you get back the link from Higher DA websites your own websites performance will be boosted for sure.
@Tony Toreto I can get you a backlink from wikipedia - not a page! Pages are much harder to do and a lot more expensive. Don't recommend doing that, unless you are very "notable/famous".
Did you use the Search Function in the forum? Why do you ask such questions, at least first read some articles about Domain Authority before starting such threads!