bp_add_activation_redirect()

function bp_add_activation_redirect() {

	// Bail if activating from network, or bulk.
	if ( isset( $_GET['activate-multi'] ) ) {
		return;
	}

	// Record that this is a new installation, so we show the right
	// welcome message.
	if ( bp_is_install() ) {
		set_transient( '_bp_is_new_install', true, 30 );
	}

	// Check in Current DB having a below 2 options are saved for the BBPress Topic & Topic Reply previously.
	$topic_slug         = get_option( '_bbp_topic_slug' );
	$topic_tag_slug     = get_option( '_bbp_topic_tag_slug' );
	$topic_archive_slug = get_option( '_bbp_topic_archive_slug' );

	if ( empty( $topic_slug ) ) {

		// Check if there is any topics their in DB.
		$topics = get_posts( array( 'post_type' => 'topic', 'numberposts' => 1 ) );

		// If found the topics then go ahead.
		if ( !empty( $topics ) ) {

			// Topics found so set the _bbp_topic_slug to "topic" instead of "discussion" otherwise it will create the issue who used previously BBPress.
			update_option( '_bbp_topic_slug', 'topic');

			// Set Flag to enable Forums default.
			update_option( 'bbp_set_forum_to_default', 'yes');

			// Get current active component.
			$bp_active_components = get_option( 'bp-active-components', array() );

			if ( ! in_array( 'forums', $bp_active_components) ) {

				// Add Forums to current components.
				$bp_active_components['forums'] = 1;

				// Set the forums to in DB.
				bp_update_option( 'bp-active-components', $bp_active_components );

			}

			// If Forums page is not set.
			$option = bp_get_option( '_bbp_root_slug_custom_slug', '' );
			if ( '' === $option ) {

				$default_title = bp_core_get_directory_page_default_titles();
				$title         = ( isset( $default_title['new_forums_page'] ) ) ? $default_title['new_forums_page'] : '';

				$new_page = array(
					'post_title'     => $title,
					'post_status'    => 'publish',
					'post_author'    => bp_loggedin_user_id(),
					'post_type'      => 'page',
					'comment_status' => 'closed',
					'ping_status'    => 'closed',
				);

				// Create Forums Page.
				$page_id = wp_insert_post( $new_page );

				bp_update_option( '_bbp_root_slug_custom_slug', $page_id );
				$slug = get_post_field( 'post_name', $page_id );

				// Set BBPress root Slug
				bp_update_option( '_bbp_root_slug', $slug );

			}

			// Reset the permalink.
			bp_update_option( 'rewrite_rules', '' );

		}

		if ( empty( $topic_archive_slug ) ) {
			update_option( '_bbp_topic_archive_slug', 'topics');
		}

		if ( empty( $topic_tag_slug ) ) {
			// Tags found so set the _bbp_topic_tag_slug to "topic-reply" instead of "discussion-reply" otherwise it will create the issue who used previously BBPress.
			update_option( '_bbp_topic_tag_slug', 'topic-tag');

		}

	}

	// Add the transient to redirect.
	set_transient( '_bp_activation_redirect', true, 30 );
}