Answer
From 24R2 onward, use IFS REST Task Configurations to parameterize the URL instead of hardcoding it in the workflow itself — set the actual per-environment value (like the CFG-specific hostname) outside the Workflow Designer, in the REST Task Configurations page, and reference that parameter from the workflow. Critically, this configuration table is deliberately excluded from environment cloning, so values you've set per-environment aren't overwritten or reset when an environment is refreshed/cloned from another one, which is exactly what makes it suitable for this per-environment-URL use case.