SOAP is quite specific and critical to data format and structure.
You might extend it, but then Edge Server is the active part and you depend on its regular "broadcast".
If Doc Server should be the active partner I'd rather suggest to use JDBC in Linux.
Your actual $get might be embedded as a Method projected as SQL Procedure that you call.
There exist examples to even execute COS commands by that approach:
see: ObjectScript over ODBC

%SYS.NLS.Locale  is the class to achieve this.
though it's not so funny
seems to be wrapper around ^%NLS and ^%SYS.NLS

Your keywords >90% COS + SAMPLES indicate your background.
if you don't intend to win a prize in a contest adapting some CSP Samples will be fastest. Forget any ZEN.
And just call the CSP class. never the .CSP itself.
what I mean:
NOT http://localhost:56773/csp/samples/form.csp
BUT http://localhost:56773/csp/samples/csp.form.CLS

It's my quick and dirty approach

from:
https://docs.jsonata.org/date-time#:~:text=JSON%20does%20not%20have%20a,%3A45%3A00.000Z%22%20%7D

for ISO 8301 
#1)  your source has to be a %TimeStamp aka. ODBC format
#2) it requires a LogicalToXSD() transformation.

>
write ##class(%Library.TimeStamp).LogicalToXSD($ZDT($Now(),3,,4))
2022-08-27T22:54:48.8953Z

But there is no defined Standard.

if it is a straight 8bit DB  you have the challenge to find out
how characters beyond the primitive 7bit ASCII are stored  e.g. ÀöÜß € ¡¿ è & é ç
is it ISO Latin 1 , 2 ,3 4, 5 ... or any of the horrible Win encondings

2 mistakes: 
#1^$get(node) delivers the content of variable node
but you would expect the result of $get(@node)  using node as global reference

#2) the better way is to use the implicit GET
Set node = $Query(^FromExtraMed(""),1,value)
write value  

it is basically using CPIPE out of a CSP page.
Article Execute Server Commands from Caché / Ensemble / IRIS

for DOCKER:
docker exec -it [-u root] <container-name or -id>  bash
details

check this: 
https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=EHTTP_inbound#EHTTP_creating_bus_service_config
especially this: 
https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY...

The URL is then http://your-server-ip:your-port/

It works if you do it better than just copy/paste  from browser
See this: 
https://community.intersystems.com/post/basic-objectscript-not-working-linux-command-line#comment-197376 
and this:
https://community.intersystems.com/post/basic-objectscript-not-working-linux-command-line#comment-197371