How to make the transition to the main?

Question

WordPress

Help solve the problem. I created a button on the site in the "Submit news" menu, when I fill in all the fields in the form, I click send, the proposed news is sent to the administrator for consideration. But the problem is that when sending news on behalf of the Guest, the error is 404, but the news is in the admin panel. How can I make it so that after sending I was transferred to the main page and not a 404 error occurred? How to disable registration and login so that guests can leave in the form? Such an error occurs for guests if they write on behalf of the admin, then everything is in order, it translates to the news page that they wrote, and the guest goes to the error page.
The screenshot of the error and the button on the
Admin site translates to the news that I threw off
This is my site with a button in the menu "Offer news" https://kostroma44rus.tk/
Thank you very much in advance. In general, you need to completely disable registration and login so that everyone is on the same level