No Wordpress, no admin panel, nothing but just plain and basic website coding in a couple of files.
As the blog gained more visitors we have included OpenCart for a store connected to this blog.
Currently, all of the blog pages are separated from the store and this is clearly visible.
On all of the blog pages, the same header file (header.htm) is included in the page.
This is not the same header we use in the OpenCart store part of our website.
We would love to have OpenCarts header file (header.twig) included on all those pages instead.
Also the footer file (footer.twig) should be included on all the blog pages.
Both headers' and footers' functions should be kept:
Search bar, shopping cart, footer links, etc...
I've found the topic below, but it's for an old OC version that still uses TPL files instead of TWIG.
viewtopic.php?p=274363#p274363
OC version 3.0.3.2
PHP version 7.2.10
Default theme
Any developer who could do this for a reasonable price?

We're a small store that doesn't sell a lot so we don't have a large budget for a huge admin panel extension for a blog or a very large custom job. I'm completely open to any advice or suggestions, ofcourse.