Force TaxJar to use POS store shipping address

functions.php

<?php 
// add to your functions.php file

function apply_pos_forced_shipping_address( $order, $request, $creating ) {
  // only apply on order creation
  if ( ! $creating ) {
    return $order;
  }
  
  // only apply for POS orders
  if( ! function_exists('woocommerce_pos_request') || ! woocommerce_pos_request() )
    return $order;    
  }

	$forced = [
		'first_name' => 'Warehouse',
		'last_name'  => 'Team',
		'company'    => 'Acme Inc.',
		'address_1'  => '1 Infinite Loop',
		'address_2'  => '',
		'city'       => 'Cupertino',
		'state'      => 'CA',
		'postcode'   => '95014',
		'country'    => 'US',
	];

	// Loop over the map and call the matching WC_Order setter.
	foreach ( $forced as $key => $value ) {
		$setter = "set_shipping_{$key}";
		if ( method_exists( $order, $setter ) ) {
			$order->$setter( $value );
		}
	}

	return $order;
}

add_filter( 'woocommerce_rest_pre_insert_shop_order_object', 'apply_pos_forced_shipping_address', 20, 3 );