improving DA (Ahrefs) of a website from 47 to at least 55

the website serbianmonitor.com proposes daily updated news about the Republic of Serbia both in English and in Italian. Right now has a DA of 47, but we really think it can reach a better DA with a good SEO support. The articles published are both translations of articles previously published in Serbian by the main local news websites and original articles written by our editors.
In particular, we need to promote the original content since it is considered very informative but it didn't get a great audience.