Hi Matt,
Ok I was testing it on:
https://www.weigh-till.co.uk/weighing-scales/compact-scales/
I have put the html code in the index.html file here.
The .htaccess is in the same folder as the index.html
public_html
weighing-scales
compact-scales
.htaccess
IfModule mod_rewrite.c
RewriteEngine On
RewriteRule ^compact-scales/.*$ index.html
/IfModule