Unique Key in Candidate Job Application Extensible Flexfield Multiple Rows

Summary:

We're using multiple rows candidate job application extensible flexfields. But we don't want users to put the unique every time they enter a new row. Is there something that could be done in backend so whenever a new row is added, a unique key is automatically generated and stored in a read-only field hidden field.

In responsive pages, we used to have value sets coupled with timestamping to solve this, but the same is not working in redwood.

Anybody found any alternate or any other solution?

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