high authority

when i start my content hub my authority score was 2 then today i see my authority score is 7 in semrush but i didn't do any backlinks but the articles i was publish they rank in 2 ..5..6..3.. , can u tell me why my authority score went from 2 to 7

you're probably using an expired / non-dropped domain that still has some links (so, authority) attached to it.

If that's not it, then probably Semrush is giving false info... or maybe they calculate a site's authority based on factors others than backlinks. But I don't use Semrush so I don't know...

Have a look at Semrush' explanation, maybe you find the answer...
https://www.semrush.com/blog/semrush-authority-score-explained/