In OmniStudio Integration Procedures, when referencing data from a prior step in the HTTP Action URL, the correct merge code syntax is:

%ElementName.PropertyName%

So, referencing a value called Date from a step named SetValues must be written as:

%SetValues.Date%

This is the format recognized by the OmniStudio Merge Language (OML) for dynamic value substitution in URLs or headers.

Incorrect Options:

A. Invalid syntax – not recognized by OmniStudio merge logic.

B. {{SetValues.Date}} is used in FlexCards, not in Integration Procedures.

D. %SetValues: Date% is incorrect merge syntax due to space and colon use.

Salesforce OmniStudio Documentation → Merge Code Syntax for Integration Procedures