Why data is not recorded if the field is hidden?

I made a conditional field that it would be hidden if it is filled and expected to receive the data in backend. Ironically, it is blank in backend.

I think one of the reasons is that, because we consider hidden fields as not required and shouldn't be filled.

In the form, you have the option in the preferences to disable/enable "Clear a field on hide", but this is only applicable in the form view. So, even if this option is disabled, the values in the hidden fields are automatically deleted when submit button is clicked, no data is captured.

Thanks

Can I request to capture data even if the field is hidden?

If you want to capture a data then you must make the field visible. There is no other way around. Usually hidden fields are used for internal purposes, when editing the submission for approval or so is required.

Please let us know what would be the scenario so we can understand better what you need to accomplish.