This is a simple mapping system using Ordnance Survey open data. Use is free of charge with a money back guarantee.
Try https://find.me.uk/ followed by a postcode. You can also do a DNS "LOC" lookup for [postcode].find.me.uk
The URL after https://find.me.uk/ can contain a number of / separated fields in any order.
The URL can end with a file type after a dot. The only one that matters is .svg which causes an SVG to be served, else an HTML is served.
If no size is set then HTML has a simple onload that reloads with the page size. If size is set then an SVG is embedded in the HTML and an onresize will reload with a change of size.
To embed in another page as a map, sadly, this SVG does not work in an img tag, it seems, so use an iframe and set width and height and maybe set no padding/margin either to avoid scroll bars..