This milestone is part of Phase 2 which adds support for Multiple Environment using Paragon-enabled datasources.
Right now it is a limitation from the Paragon's end which their team is working on.

"We are working on adding support for X-Paragon-Credential which will be a UUID reference to the credential object. If you pass this header, it will explicitly select the account to use to run that action. It is not available yet, but I’ll keep you posted — should be live in the next 2 weeks."
Ref: https://theappsmith.slack.com/archives/C07NTH2TH3M/p1737007096987959?thread_ts=1735885574.338189&cid=C07NTH2TH3M