Hey @JIMENEZ_POMARETA_Ram and @ctejo,
The Capture app does not properly support scripts in custom forms, as you have noticed.
Is it possible to make the assignments you need based on program rules? Assignment should work in custom forms like they do in default forms. Could you describe the assignment conceptually?
The custom form javascript might be added back to the Capture app either as part of the custom form functionality or by other means. To chart the path here your input is valuable.
Best regards,
Markus