You have requested a non-existent service "entity.manager"

Problem/Motivation

When we visit this path admin/structure/invite/add it shows below error and if we use block the extra added field in not shown in block (missing custom field)

The website encountered an unexpected error. Please try again later.

Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException: You have requested a non-existent service "entity.manager". in Drupal\Component\DependencyInjection\Container->get() (line 156 of core/lib/Drupal/Component/DependencyInjection/Container.php).
Drupal\invite\Form\InviteForm::create(Object) (Line: 28)
Drupal\Core\DependencyInjection\ClassResolver->getInstanceFromDefinition('Drupal\invite\Form\InviteForm') (Line: 210)
Drupal\Core\Entity\EntityTypeManager->getFormObject('invite', 'add') (Line: 69)
Drupal\Core\Entity\HtmlEntityFormController->getFormObject(Object, 'invite.add.default') (Line: 58)
Drupal\Core\Controller\FormController->getContentResult(Object, Object) (Line: 39)
Drupal\layout_builder\Controller\LayoutBuilderHtmlEntityFormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 564)
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: 158)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 80)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 709)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Proposed resolution

src/Form/InviteForm.php using "$container->get('entity.manager')," which seems not compatible with 9

Please suggest if there is any other way to make custom added fields visible in block.

Thanks!