How to extend menu bar size

Sorry, but you’re using a premium/paid theme. It’s best to go to the support site where you bought the theme – https://themeforest.net/ – for help with customizations and issues. You paid for support when you bought the theme, so you should contact the people who sold you the theme.

These forums are for free themes available in the WordPress theme directory at https://www.ads-software.com/themes/. See https://codex.www.ads-software.com/Forum_Welcome#Commercial_Products

Hi, songdogtech
i didn’t bought paid theme. i downloaded it from [ redacted ] for free.

Yes, you downloaded it for “free”. That means you stole it. The style sheet header says:

Theme Name: Core (shared on wplocker.com)
Description: Premium Template for Photography Portfolio
Version: 5.5.1
Author: Peerapong Pulpipatnan
Author URI: https://themeforest.net/user/peerapong

That’s a paid theme from themeforest.net.