How to edit site name

I’m trying to edit the “site name” for each different page on this website here:
https://resquaredmedical.com/

If I’m not being clear enough, here’s a page example, a screenshot, and code of what I’m referring to.

1. Page ex: https://resquaredmedical.com/refocus/
2. Screenshot: https://prnt.sc/fvs5fl

3. Code:
<meta property=”og:site_name” content=”IV Hydration Therapy & Hangover Cure | ReSquared Medical | Las Vegas”>

Does anyone know where to edit that? Help would be much appreciated.

Thanks