Can a custom Block be added to a Wix Post

I have a custom Block/app for my site and can see and add it to a Page.

But I cannot see how to add it to a Blog Post.

The idea is build a Block that allows my Collaborator to add them to blog post and take out the need for them to mess about with embed codes that they consistently mess up or forget how to edit them to show new content etc.

Is it actually possible to add a custom Block to a Blog post?.

Cheers