i have a  500 internal server error when trying to access odoo server which is running. in log it shows this error message: "The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol."

i know that i have to add this < meta charset="utf-8" > but idk where