It works once I fixed the URL. I had another issue with deep linking, but I’ll take that to github.
Thanks for the reply, yes I am using the platform rather than the tool plugin so this is indeed the wrong forum. I think my problem may be the same as one noted in GitHub with Moodle – https://github.com/celtic-project/wordpress-lti-platform/issues/5#issuecomment-1761423395 – the generated URL is invalid at the tool side. I’ll try to fix this up and see if that solves it.
