Thank you Eduard.
At this time, we use JDBC connection and INSERT sql command from panda but we look for a more integrated way to do that.

You're sure about that?
I understand these methods should only be used when the list property comes from a %Persistent object, but new instance with %New method is not allowed.

%Collection.ListOfDT Serialize and deserialize methods seem like doing the trick.
But I found the documentation is a little bit ambiguous as the sample in the header refers itself to %ListOfDataTypes.

https://docs.intersystems.com/iris20201/csp/documatic/%25CSP.Documatic.c...

Oh great!
Please InterSystems developers, make these useful methods public and supported ;-)

thanks @Eduard Lebedyuk 
Yes it works great. that's the way we did it. So no direct straight serialization system function. ;-)

Thank you @Eduard Lebedyuk and @Jeffrey Drumm 
We decided not to hide properties until GA.
 

thank you Evgeny!

thank you Vitaliy.
Perfect.

it's more a send and forget kind of thing but we will add a deferred response from production B to production A.

Thanks Marc.

We think of writing a REST API to send the IDs of the messages to be sent to production B. The production B service will then read the appropriate records in the mapped table.

Interesting point Jenna. Thanks.
I'll try that!

Thanks a lot Warlin!

I also found the documentation on that subject: %Status Error Processing

Thanks Eduard. As I understand, these articles address authorization flow for confidential client.
I would need a oauth2 flow compatible with an angular public client and the recommended one for this kind of client is code flow + PKCE.
Anyone experience this kind authorization flow with IRIS as server?

For those who are interested, here is an good article on the ≠ between implicit flow and code flow with PKCE:
https://christianlydemann.com/implicit-flow-vs-code-flow-with-pkce/

This is a very interesting option in my context.
Thank you Evgeny!

Thank you Ward! I will keep this as a good option.