bmitted_data ) {
		$options = array(
			array(
				'name'  => 'hustle_is_submit',
				'type'  => 'hidden',
				'value' => '1',
			),
		);

		if ( $this->is_allow_multi_on_form() ) {
			$options[] = array(
				'name'  => 'multi_id',
				'type'  => 'hidden',
				'value' => isset( $submitted_data['multi_id'] ) ? $submitted_data['multi_id'] : $this->generate_multi_id(),
			);
		}

		if ( $this->is_allow_multi_on_global() ) {
			$options[] = array(
				'name'  => 'global_multi_id',
				'type'  => 'hidden',
				'value' => isset( $submitted_data['global_multi_id'] ) ? $submitted_data['global_multi_id'] : $this->generate_multi_id(),
			);
		}
		$html = Hustle_Provider_Utils::get_html_for_options( $options );
		$html = apply_filters( 'hustle_providers_admin_add_common_hidden_fields', $html );
		return $html;
	}

	/**
	 * In version 3.0 provider details like API key and URL were stored at module level,
	 * now they are stored globally to avoid duplication.
	 *
	 * This method addresses this difference.
	 *
	 * @param Hustle_Module_Model $module     Current module.
	 * @param Object              $old_module Old module.
	 *
	 * @return bool
	 */
	public function migrate_30( $module, $old_module ) {
		$v3_provider = ! empty( $old_module->meta['content']['email_services'][ $this->get_slug() ] )
			? $old_module->meta['content']['email_services'][ $this->get_slug() ]
			: false;

		if ( empty( $v3_provider ) || $this->get_30_provider_mappings() === false ) {
			// Nothing to migrate.
			return false;
		}

		$v3_provider_active = '1' === $v3_provider['enabled'];

		// If the provider doesn't already exist globally, add it.
		$global_multi_id = $this->get_30_migrated_provider( $v3_provider );
		if ( empty( $global_multi_id ) ) {
			$global_multi_id = $this->generate_multi_id();
			$this->save_multi_settings_values(
				$global_multi_id,
				$this->map_30_provider( $v3_provider )
			);

			// Activate the addon.
			Hustle_Providers::get_instance()->activate_addon( $this->get_slug() );
		}

		// Link the provider to the module.
		if ( $v3_provider_active ) {
			$module_provider_link                             = $this->strip_30_global_provider_settings( $v3_provider );
			$module_provider_link['selected_global_multi_id'] = $global_multi_id;

			$module->set_provider_settings( $this->get_slug(), $module_provider_link );
		}

		return true;
	}

	/**
	 * Map the provider's field from the old settings to the new ones.
	 *
	 * @since 4.0.0
	 * @param array $v3_provider Old settings of the provider.
	 */
	private function map_30_provider( $v3_provider ) {
		$v4_provider = array();
		$mappings    = $this->get_30_provider_mappings();

		foreach ( $mappings as $v3_index => $v4_index ) {
			if ( isset( $v3_provider[ $v3_index ] ) ) {
				$v4_provider[ $v4_index ] = $v3_provider[ $v3_index ];
			}
		}

		return $v4_provider;
	}

	/**
	 * Gets the provider's map for the 3.x to 4.x migration.
	 *
	 * @since 4.0.0
	 * @return false|array
	 */
	protected function get_30_provider_mappings() {
		return false;
	}

	/**
	 * If a provider has already been migrated from 3.0 this method will return its id.
	 *
	 * @param array $v3_provider Old settings of the provider.
	 *
	 * @return bool|string Global multi ID
	 */
	private function get_30_migrated_provider( $v3_provider ) {
		$v40_providers      = $this->get_settings_values();
		$mapped_40_provider = $this->map_30_provider( $v3_provider );

		foreach ( $v40_providers as $global_multi_id => $v40_provider ) {
			if ( $v40_provider === $mapped_40_provider ) {
				return $global_multi_id;
			}
		}

		return false;
	}

	/**
	 * Strips unused old settings for the provider.
	 *
	 * @since 4.0.0
	 *
	 * @param array $v3_provider Old provider's settings.
	 * @return array
	 */
	private function strip_30_global_provider_settings( $v3_provider ) {
		$copy                     = array();
		$global_provider_settings = array_merge(
			array( 'enabled', 'optin_provider_name', 'desc' ),
			array_keys( $this->get_30_provider_mappings() )
		);

		foreach ( $v3_provider as $item => $value ) {
			if ( in_array( $item, $global_provider_settings, true ) ) {
				continue;
			}

			$copy[ $item ] = $value;
		}

		return $copy;
	}

	/**
	 * If a provider fails to connect,
	 * returns a generic message.
	 *
	 * @since 4.0.0
	 *
	 * @return string error message
	 */
	protected function provider_connection_falied() {
		/* translators: provider's title */
		$error_message = sprintf( __( "We couldn't connect to your %s account. Please resolve the errors below and try again.", 'hustle' ), $this->title );
		return $error_message;
	}
}