For example on https://veronika.mb-themes.com/for-sale if we open SEO tools there is a list of headers like:
<H3> Search
<H4> Keyword
<H4> Location
<H4> Transaction
<H4> Condition
<H4> Period
<H4> Price:
<H6> Sample dropdown
<H2> Subscribe to alert
<H2> Subscribe to alert
<H2> Subscribe to alert
<H6> Sample dropdown
<H2> Subscribe to alert
<H2> Subscribe to alert
<H2> Subscribe to alert

Why we need "<H2> Subscribe to alert" so many, and how to remove them?

@rumiour
You can modify it in alert file of theme.