Minor change.

src/Form/SettingsForm.php

@@ -2,11 +2,8 @@
 
 namespace Drupal\geocoder\Form;
 
-use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Config\TypedConfigManagerInterface;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * The geocoder settings form.
@@ -32,15 +29,17 @@ class SettingsForm extends ConfigFormBase {
    */
   public function buildForm(array $form, FormStateInterface $form_state) {
     $config = $this->config('geocoder.settings');
+    // Checking the typedConfigManager - property exists in ConfigFormBase.
     if (property_exists(ConfigFormBase::class, 'typedConfigManager')) {
       $geocoder_config_schema = $this->typedConfigManager->getDefinition('geocoder.settings') + ['mapping' => []];
     }
     else {
       // Handling backward compatiblity before D10.2
-      // Calling typedConfigManager() of  ConfigFormBase class. 
-      $geocoder_config_schema = $this->typedConfigManager();
+      // Calling typedConfigManager() of  ConfigFormBase class.
+      $typedConfigManager = $this->typedConfigManager();
+      $geocoder_config_schema = $typedConfigManager->getDefinition('geocoder.settings') + ['mapping' => []];
     }
-    
+
     $geocoder_config_schema = $geocoder_config_schema['mapping'];
 
     // Attach Geofield Map Library.