How to add custom content or static HTML below dynamic coupon listings in a PHP-based store page? [closed]

I purchased a PHP-based coupon theme for my site, and I’m trying to customize the store pages. Here’s an example page: https://flashvoucher.com/store/a2-hosting

Currently, the page shows the list of coupons dynamically fetched from the database. However, there’s no option in the theme settings to add static content (like a small paragraph or HTML block) below the coupon list. I want to add some SEO-friendly text, maybe 200–300 words about the store, right after the coupons end.

The theme uses PHP templates and seems to be built using procedural PHP (not any modern frameworks). I can edit the template files directly.

Question:
What would be the best way to inject custom content (manually or via admin, if possible) just below the dynamic content block? Should I:

Modify the template file and hardcode the HTML block?

Use output buffering or hooks (if available)?

Append content via controller logic if it exists?

Any advice or code example would be appreciated.