How to properly get rid of duplicate h1 headings?

Question

Search Engine Optimization

Site analysis shows that I have 3 h1 headers on each page)

How does this happen?

The template contains the name of the site - this is the h1 tag.

But even the uncle who compiled it made it so that for the mobile version a piece of code with the site name is duplicated and simply not displayed until it is switched to the mobile version, BUT the PS is analyzed as a repeating h1.

Now comes the denouement: Create page => Enter page title => Publish - bingo, we have a third h1 on the page.

How in this case to bring everything to human SEO - one h1 per page?

Edit template?