The best option may be to use a scripting component to pass in the existing array of values and the new code/value to be appended.
I haven't done this exact thing, but here is an example using the Javascript component to bring in a string of Names separated by semicolon's and then output them as an array. Note how inputNames and nameList.nameElement are declared in the script component, and then how they are processed in the javascript as input and then returned as output.

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Dan Gage
Principal Solution Consultant
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Original Message:
Sent: 04-10-2023 07:29
From: Utsa Das
Subject: Update reference data source mapping through RIH
Hi ,
I am trying those steps already but in the second step I am unable to append the new source mapping into the existing Data mapping returned from step 1 .Could you please guide here hot to do the same in RIH as I am not able to find the suitable function to achieve this ?
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Utsa Das
Syneos
Original Message:
Sent: 04-08-2023 06:19
From: Ashish Rawat
Subject: Update reference data source mapping through RIH
This is a two step process
1. Pull the existing lookup JSON via GET {{RDMTenantURL}}/lookups/{{RDMTenant}}/<<LOOKUP_CODE>>
2. Append the new source mapping and post updated JSON via POST {{RDMTenantURL}}/lookups/{{RDMTenant}}/
PS: You can automate above steps via RIH
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Ashish Rawat
Manager
Fresh Gravity
Bangalore
Original Message:
Sent: 04-07-2023 11:21
From: Utsa Das
Subject: Update reference data source mapping through RIH
Hi Team,
We are getting code-value pair from a new source system and want to add the same into an existing canonical value which has other code-value pairs from different source systems inside RDM. Now the challenge is if I load the code value pair from the new source system through RDM put call it will wipe out all the other values and keep only this pair.So someway we need to add the new code value pair with the existing pairs and send the whole response to RDM (basically a partial override kind a thing in RDM).So can you suggest if we can do achieve this someway through RIH recipe ?
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Utsa Das
Syneos
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