Increase website domain authority

Provide internal links and unique content.

It depends upon quality of content and backlinks to improve your website.

Use highquality backlinks

You know what..... Banks are happy to give loan to someone who really doesn't need it. And they really don't want to give loan to someone who needs it.

In exactly the same way..... Domain Authority (higher DA) is given to a website that really doesn't care if it is having good DA or not. Let me explain...

These days... higher DA is given to a website that has.... (a) high traffic, (b) high engagement, and (c) high popularity. When a website got all these things then will it really care if it's DA is high or low?

The best advice is... FORGET about DA and focus on user engagement and popularity (which will leads to high traffic by itself). So, what to do...

(1) Create a fast-loading + AMP website
(2) Have engaging content (all types.... images, videos, textual, embedded pdf, etc.)
(3) Do a lot of social media; try to go viral.
(4) For sure, you need to do some natural quality link-building (have a wide range of link profile)

BTW... this is a concise to-do list of whole SEO thing.

IF the content is really interesting and of good quality in all means like text, images...etc surely it will be increase.

Just focus on organic traffic then DA will show your metrics score.

Work on your On-page and Off-page SEO. And make quality content