double quotes on a sql server code inside powershell - in visual code - how to make it work?

double quotes are used in sql server, and their behaviour can be defined by the option SET QUOTED_IDENTIFIER ON \ OFF double quotes are also used in powershell . SET QUOTED_IDENTIFIER must be ON when you invoke XML data type methods. this is a partial view of a stored procedure that I want to deploy to multiple servers, however, because of the quoted-identifier, or double quotes this character - " - it is not working in powershell, in the visual code that I use to deploy.

DECLARE @WebXConfigurationID INT,
				@stored_URL VARCHAR(2000), @cur_URL VARCHAR(2000), 
				@stored_OpsServiceURL VARCHAR(2000), @cur_OPSServiceURL  VARCHAR(2000),
				@cur_Properties XML;


			PRINT 'WebX Configuration: ' + CAST(@WebXConfigurationID AS VARCHAR(20));

			IF (ISNULL(@stored_URL, '')  ISNULL(@cur_URL, ''))
			BEGIN
				PRINT '	- Base URL needs updating'
			END 
			ELSE
			BEGIN
				PRINT '	- Base URL does not need updating'
			END;

			IF (ISNULL(@stored_OpsServiceURL, '')  ISNULL(@cur_OPSServiceURL, '') AND @cur_OPSServiceURL IS NOT NULL)
			BEGIN
				PRINT '	- OPS Service URL needs updating'
				SET @cur_Properties.modify('replace value of (/properties[1] //OPSServiceURL[1] /text())[1]  with sql:variable("@stored_OpsServiceURL")')
			END 
			ELSE
			BEGIN
				PRINT '	- OPS Service URL does not need updating'
			END;

this is the error message:

"' in expression or statement.
At C:\sp_PosRestore.ps1:636 char:114
+ ... ServiceURL[1] /text())[1]  with sql:variable("@stored_OpsServiceURL")')
+                                                 ~~~~~~~~~~~~~~~~~~~~~
The splatting operator '@' cannot be used to reference variables in an expression. '@stored_OpsServiceURL' can be used only as an argument to a command. To reference variables in an expression use      
'$stored_OpsServiceURL'.
    + CategoryInfo          : ParserError: (:) [], ParseException
    + FullyQualifiedErrorId : UnexpectedToken

The Powershell code:

$SQLQuery = 
"
DECLARE @WebXConfigurationID INT,
				@stored_URL VARCHAR(2000), @cur_URL VARCHAR(2000), 
				@stored_OpsServiceURL VARCHAR(2000), @cur_OPSServiceURL  VARCHAR(2000),
				@cur_Properties XML;


			PRINT 'WebX Configuration: ' + CAST(@WebXConfigurationID AS VARCHAR(20));

			IF (ISNULL(@stored_URL, '')  ISNULL(@cur_URL, ''))
			BEGIN
				PRINT '	- Base URL needs updating'
			END 
			ELSE
			BEGIN
				PRINT '	- Base URL does not need updating'
			END;

			IF (ISNULL(@stored_OpsServiceURL, '')  ISNULL(@cur_OPSServiceURL, '') AND @cur_OPSServiceURL IS NOT NULL)
			BEGIN
				PRINT '	- OPS Service URL needs updating'
				SET @cur_Properties.modify('replace value of (/properties[1] //OPSServiceURL[1] /text())[1]  with sql:variable("@stored_OpsServiceURL")')
			END 
			ELSE
			BEGIN
				PRINT '	- OPS Service URL does not need updating'
			END;
"