Undefined index: auto_create in line 32 AutoCreationProcessTrait.php

Notice: Undefined index: auto_create in Drupal\select2boxes\Plugin\Field\FieldWidget\MultiSelect2BoxesAutocompleteWidget::processAutoCreation() (line 32 of modules/contrib/select2boxes/src/AutoCreationProcessTrait.php).
Drupal\select2boxes\Plugin\Field\FieldWidget\MultiSelect2BoxesAutocompleteWidget::processAutoCreation(Array, , Object)
call_user_func_array(Array, Array) (Line: 1273)
Drupal\Core\Form\FormBuilder->handleInputElement('group_content_business-group_membership_add_form', Array, Object) (Line: 990)
Drupal\Core\Form\FormBuilder->doBuildForm('group_content_business-group_membership_add_form', Array, Object) (Line: 1060)
Drupal\Core\Form\FormBuilder->doBuildForm('group_content_business-group_membership_add_form', Array, Object) (Line: 1060)
Drupal\Core\Form\FormBuilder->doBuildForm('group_content_business-group_membership_add_form', Array, Object) (Line: 561)
Drupal\Core\Form\FormBuilder->processForm('group_content_business-group_membership_add_form', Array, Object) (Line: 318)
Drupal\Core\Form\FormBuilder->buildForm('group_content_business-group_membership_add_form', Object) (Line: 48)
Drupal\Core\Entity\EntityFormBuilder->getForm(Object, 'add') (Line: 237)
Drupal\group\Entity\Controller\GroupContentController->addForm(Object, 'group_membership')
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 582)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 151)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 67)
Drupal\simple_oauth\HttpMiddleware\BasicAuthSwap->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 41)
Drupal\jsonapi\StackMiddleware\FormatSetter->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 665)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)