Custom API does not have any graceful way to handle errors

### Description

Custom API section does not have any way to gracefully handling error.

It would be better to have some way to show a nice user friendly message like the one in other widgets.

Thanks

Start by locating the Custom API section and reviewing how other widgets present errors. Compare their user-facing error handling with the behavior shown in the issue, then verify that Custom API failures display a similarly clear, friendly message instead of the current result.

Written by the indexing model from the issue text.