@anwarsahil0 The decrease in DA is could be because of spammy links to your site. Audit your site's offpage thoroughly and disaow the links if you want to

A decrease in Domain Authority (DA) can be concerning, as it often reflects a decline in the overall authority and perceived credibility of your website. Domain Authority is a metric developed by Moz that predicts how well a website will rank on search engine result pages. Several factors can contribute to a decrease in DA, and addressing them can help improve your website's authority over time. Here are some common reasons for a decline in DA and potential solutions:

Low-Quality Backlinks:

Issue: Backlinks from low-quality or spammy websites can negatively impact your DA.
Solution:
Disavow toxic backlinks using Google's Disavow Tool.
Focus on building high-quality, relevant backlinks from authoritative sources.
Content Quality and Relevance:

Issue: Poor-quality content or content that is not relevant to your target audience can impact your website's authority.
Solution:
Create high-quality, valuable, and relevant content that addresses the needs of your audience.
Regularly update and refresh existing content.

Yes you can create a forum backlink for a digital marketing website . Make sure to get relevant forum backlink related to your niche as it will be more beneficial