How will the search engine react to the changing h1?

Question

Search Engine Optimization

On my site, when loading h1, it has the value 'Header1'
After loading the site, through js, the text changes in a circle to 'Header2' and back
. How will search engines react to this?

Answer 1

They will not see the changes, i.e. only “Heading 1” will exist for them.
Search engines index only the content of which is in the markup initially, since js creates content only when the user enters the page. The robot, indexing the page, will not run the script, so it will not know that h1 has changed.

Answer 2

check the JS console through the webmaster
is not very reliable, with a lot of assumptions and errors, the bot may not be what you want to see at all and suspect you