Adjusting headlines for SEO h6->h2

[manter]

Hello,  some of the sections in my theme have h6 and I need to make them h2 for SEO purposes. Example attached. What would be the easiest way to edit them to h2? I know I could change the code, but honestly, I cannot find the right files where to change h6 to h2.  I also attach shopify interface, maybe I can simply do changes in this custom CSS field?

Would gladly tip someone who'll help me.

Webpage is: https://holycup.lt/

Thanks!

[suyash1]

@manter  - as @Ecom_Dev mentioned, you will need to go to theme files, you will need to check which section is used and edit that particular section liquid file to change h6 to h2