add new post can't custom fontmatter

i use hexo-admin to create a new post, it is amazing but i cant find where to custom the font-matter block, i want to custom my blog's top image use fontmatter with theme plugin ablility. but i cant find where to do this.

No file, test, or entry point is named. Start by tracing the new-post flow in the repository and determine how its front-matter block is assembled; done means users can customize that block when creating a post, including fields needed by theme plugins.

Written by the indexing model from the issue text.