Snippet to change UPS account details in rate request when Access Point address has been selected. WooCommerce UPS Shipping Plugin with Print Label by PluginHive - https://www.pluginhive.com/product/woocommerce-ups-shipping-plugin-with-print-label/

functions.php

/**
 * Snippet to change UPS account details in rate request when Access Point address has been selected.
 * Created at : 27 Aug 2018
 * Updated at : 27 Aug 2018
 * PluginHive Plugins : https://www.pluginhive.com/plugins/
 * Gist Link : https://gist.github.com/xadapter/8891ba54b0cd2a642813e83e1d7e9810
 */

if( ! function_exists('ph_change_ups_account_for_accesspoint_rate_request') ) {
	function ph_change_ups_account_for_accesspoint_rate_request( $xml_request, $package ){

		// UPS account details that has been configured in plugin settings page
		$general_ups_account_details = array(
			'user_id'		=>	'ups_user_id',
			'password'		=>	'ups_password',
			'access_key'	=>	'ups_access_key',
			'acc_no'		=>	'ups_acc_no'
		);

		// UPS account details to be used in rate request if Access point has been selected
		$access_point_ups_account_details = array(
			'user_id'		=>	'access_point_user_id',
			'password'		=>	'access_point_password',
			'access_key'	=>	'access_point_access_key',
			'acc_no'		=>	'access_point_acc_no'
		);


		$xml_request_arr = explode( '<RatingServiceSelectionRequest>', $xml_request );
		$xml_request_arr[1] = '<RatingServiceSelectionRequest>'.$xml_request_arr[1];
		$xml_request_arr_obj_1 = new SimpleXMLElement($xml_request_arr[1]);
		$shipment_indication_code = ! empty($xml_request_arr_obj_1->Shipment->ShipmentIndicationType) ? trim((string) $xml_request_arr_obj_1->Shipment->ShipmentIndicationType->Code) : null;

		// Replace the account details when Accesspoint has been selected
		if( $shipment_indication_code == '02' || $shipment_indication_code == '01' ) {
			$xml_request = str_replace( $general_ups_account_details, $access_point_ups_account_details, $xml_request );
		}
		return $xml_request;
	}

	add_filter( 'wf_ups_rate_request', 'ph_change_ups_account_for_accesspoint_rate_request', 10, 2 );
}