functions.php

<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}
if ( ! function_exists( 'sim_fs' ) ) {
	/**
	 * If the global variable  is not set, then include the Freemius SDK, initialize it with the
	 * above parameters, and set the global variable  to the result of the initialization
	 *
	 * @return $sim_fs Freemius SDK instance
	 */
	 * /
	function sim_fs() {
		 global $sim_fs;

		if ( ! isset( $sim_fs ) ) {
			// Include Freemius SDK.
			require_once dirname( __FILE__ ) . '/freemius/start.php';

			$sim_fs = fs_dynamic_init(
				array(
					'id'             => '10999',
					'slug'           => 'simplifii',
					'type'           => 'theme',
					'public_key'     => 'pk_dcceb7c5540d2fb5c0ae4ff184bab',
					'is_premium'     => false,
					'has_addons'     => false,
					'has_paid_plans' => false,
					'menu'           => array(
						'slug'    => 'simplifii',
						'parent'  => array(
							'slug' => 'themes.php',
						),
						'account' => true,
					),
				)
			);
		}

		return $sim_fs;
	}

	// Init Freemius.
	sim_fs();

	// Signal that SDK was initiated.
	do_action( 'sim_fs_loaded' );
}

function sim_fs_custom_connect_message_on_update(
	$message,
	$user_first_name,
	$theme_title,
	$user_login,
	$site_link,
	$freemius_link
) {
	return sprintf(
		__( 'Hey %1$s', 'simplifii' ) . ',<br>' .
			__( 'Please help us improve %2$s! If you opt-in, some data about your usage of %2$s will be sent to %5$s. If you skip this, that\'s okay! %2$s will still work just fine.', 'simplifii' ),
		$user_first_name,
		'<b>' . $theme_title . '</b>',
		'<b>' . $user_login . '</b>',
		$site_link,
		$freemius_link
	);
}

sim_fs()->add_filter( 'connect_message_on_update', 'sim_fs_custom_connect_message_on_update', 10, 6 );

/**
 * Simplifii functions and definitions
 *
 * @link https://developer.wordpress.org/themes/basics/theme-functions/
 *
 * @package WordPress
 * @subpackage Simplifii
 * @since Simplifii 1.0
 */
if ( ! function_exists( 'simplifii_setup' ) ) {


	/**
	 * It adds support for the theme to use HTML5 markup, post thumbnails, and automatic feed links
	 */
	function simplifii_setup() {
		load_theme_textdomain( 'simplifii', get_template_directory() . '/languages' );

		// Add default posts and comments RSS feed links to head.
		add_theme_support( 'automatic-feed-links' );

		// Add support for responsive embedded content.
		add_theme_support( 'responsive-embeds' );

		// WooCommerce support
		add_theme_support( 'woocommerce' );

		// Add support for editor styles.
		add_theme_support( 'editor-styles' );

		// Enqueue editor styles.
		add_editor_style( 'style.css' );

		// add optin wp block styles
		add_theme_support( 'wp-block-styles' );
	}
	add_action( 'after_setup_theme', 'simplifii_setup' );
}


if ( ! function_exists( 'simplifii_styles' ) ) {

	/**
	 * It registers two stylesheets, then enqueues a third stylesheet that depends on the first two
	 */
	function simplifii_styles() {
		// Register theme stylesheet.
		$theme_version = wp_get_theme()->get( 'Version' );

		$version_string = is_string( $theme_version ) ? $theme_version : false;

		wp_register_style(
			'simplifii-style',
			get_template_directory_uri() . '/style.css',
			array(),
			$version_string
		);

		// Enqueue theme stylesheet.
		wp_enqueue_style( 'simplifii-style' );
	}

	add_action( 'wp_enqueue_scripts', 'simplifii_styles' );
}