Add this code into function.php of your child theme.

Please make all changes to the child theme files, and do not add the code directly to the theme files, otherwise after updating the theme your fixes will be lost

function.php

// ------------------------------------------------------
//         Groovy Menu plugin integration
// ------------------------------------------------------

// Add hook for 'avada_before_body_content' action.
add_action( 'avada_before_body_content', 'gm_custom_child_show_groovy_menu', 1 );

if ( ! function_exists( 'gm_custom_child_show_groovy_menu' ) ) {
	function gm_custom_child_show_groovy_menu() {
		if ( function_exists( 'groovy_menu' ) ) {
			groovy_menu();

			// Start output buffering.
			add_action( 'avada_before_header_wrapper', 'gm_custom_avada_child_theme_integration__start_cache', 0 );
			// Finish output buffering with clear.
			add_action( 'avada_after_header_wrapper', 'gm_custom_avada_child_theme_integration__clear_cache', 999999 );
		}
	}
}

if ( ! function_exists( 'gm_custom_avada_child_theme_integration__start_cache' ) ) {
	function gm_custom_avada_child_theme_integration__start_cache() {
		ob_start();
	}
}

if ( ! function_exists( 'gm_custom_avada_child_theme_integration__clear_cache' ) ) {
	function gm_custom_avada_child_theme_integration__clear_cache() {
		$cleared_html = ob_get_clean();
		unset( $cleared_html );
	}
}

style.css


/*
Theme Name: Avada Child (GroovyMenu)
Theme URI: http://avada.theme-fusion.com/
Template: Avada
Description: Avada Child theme with Groovy Menu plugin integration.
Author: Grooni
Author URI: http://grooni.com/docs/groovy-menu/
Version: 1.1
*/

.gm-search__fullscreen-container .gm-search__input {
    margin: 0;
}

.gm-main-menu-wrapper .gm-minicart-dropdown .woocommerce-mini-cart__buttons {
    background: transparent;
}

/*
.avada-responsive .gm-navbar-sticky-toggle .gm-wrapper {
    padding-right: 9px !important;
}
*/

Note: You can find the child theme for the Avada theme in the Groovy Menu > Integration section