How to solved a duplicate entity record

1. What is the issue? Please be detailed.
I keyed in a duplicate barcode ID, and when i rescanned the duplicate barcode ID for follow-up of the participant, the few variable required to display did not display

2. What steps can we take to reproduce this issue?

3. What have you tried to fix the issue?
I tried to reject one record on the server, but the variables were not yet successfully pulled.
How can I solve a duplicate barcode ID?

4. Upload any forms or screenshots you can share publicly below.
I was trying out the functionality using
Add participant and participant follow-up.