we want to send the digest email at a particular day and time can you suggest me the changes i should make in any particular file
I found https://community.nodebb.org/topic/10026/nodebb-plugin-write-api-failing-to-load-admin-page solving the issue.
Did you add widget areas to the page in the template?
Please share the template
See also Where to put custom CSS file.. | NodeBB.
Another possibility is a custom css file overriding the others by having the last <link rel="stylesheet" href="..." /> line in the theme source.
I threw in an if(found) just in case - but I am always amazed by how little code is required.
That seem to happen a lot with Node.js and a well written software entitled NodeBB 👍