Hello @poomik,
Thank you for reaching out,
I’ve checked your website and saw you are using the top bar instead of the main header. The hamburger menu is available for the header, and it’s not working for the top bar.
After enabling the primary header, then you can adjust it from WP Dashboard > Appearance > Customizer > Header.
However, if you would like to keep the current menu showing on mobile devices(still, it’s not a hamburger menu), then you can
put the CSS below in Customizing > Custom CSS/JS > CSS Code:
@media only screen and (max-width: 959px) {
body.default-breakpoint #top-bar-nav,
body.default-breakpoint #site-navigation-wrap,
body.default-breakpoint .oceanwp-social-menu,
body.default-breakpoint .after-header-content {
display: block;
}
}
Result: https://postimg.cc/svxxjPr2.
Please read this link for more information about the CSS/JS code on the customizer: https://docs.oceanwp.org/article/354-add-custom-css-and-js-to-your-website.
Note: If you have any cache plugin or server cache(CDN / Browser Cache and Cookies and …), you need to clear its cache contents or disable them to see your changes. Also, remember to click on the regenerate all assets file and data in Elementor > Tools(if you have Elementor).
I hope that helps.
Best Regards