Has anyone got any advice on how to post a blog post on https://blogstack.io/

I have a profile

https://blogstack.io/u/npub1aktx8y6pl8xezd9gnaz2u5w6462mlpz2hx8qumcyg6xrpmduwj2s35c0j6

......and want to post this Substack Article:

https://iaindavis.substack.com/p/sadiq-khans-ulez-propaganda

I can login fine and have converted to Markdown that look fine in the blogstack preview. I have added Nostr Hosted Hero Image no more than 5 tags and all looks good.

But publishing just doesn't happen.

Any tips would be greatly appreciated.