cant use @id in attribute name

@ is not allowed by elm.setAttribute() so i'ts not possible to use attribute like widget-@id

test:

document.body.setAttribute('test@test','test')
// InvalidCharacterError: String contains an invalid character

suggestion: replace unauthorized invalid characters by another, for example _

<sib-display
  data-src='https://test-paris.happy-dev.fr/members/'
  data-fields='@id'
  widget-_id='sib-form-label-text'
>