Over the years, a few people have asked about getting data out of a Numbas test without running it inside a VLE or the LTI tool.
I've made a small demo showing how to embed a Numbas exam in a page, then in the parent page I've reused the SCORM API from the Numbas LTI tool to record data from the Numbas exam. The exam package has to be hosted on the same domain as the containing page, so it's not quite as simple as using the embed URL that the Numbas editor gives you.
It doesn't save the data anywhere - that's something you'd have to set up yourself, either reusing the code from the LTI tool, or by writing your own.
Think carefully before attempting this: the LTI tool does a lot of stuff, like managing user accounts, handling connection problems and applying availability date restrictions, that you'd have to reimplement.