in django-formset pypi package Uncaught (in promise) SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

when i try implement django-formset package selectize and preselect option show the error Uncaught (in promise) SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

plz help to solve this issue