modules/custom/d_product/src/Plugin/Block/ResetButton.php
public function blockForm($form, FormStateInterface $form_state) {
    $form['button_text'] = [
      '#type' => 'textfield',
      '#title' => t('Button text'),
      '#default_value' => $this->configuration['button_text'] ?? 'Reset Filters',
    ];

    $form['button_class'] = [
      '#type' => 'textfield',
      '#title' => t('Button class'),
      '#default_value' => $this->configuration['button_class'] ?? 'btn btn-outline-primary btn-sm btn-reset',
    ];

    $form['button_target'] = [
      '#type' => 'textfield',
      '#title' => t('Button target'),
      '#default_value' => $this->configuration['button_target'] ?? '/products',
    ];

    $form['button_icon_class'] = [
      '#type' => 'textfield',
      '#title' => t('Button icon class'),
      '#default_value' => $this->configuration['button_icon_class'] ?? 'fas fa-times',
    ];

    return $form;
  }
public function blockForm($form, FormStateInterface $form_state) {
    $form['button_text'] = [
      '#type' => 'textfield',
      '#title' => t('Button text'),
      '#default_value' => $this->configuration['button_text'] ?? 'Reset Filters',
    ];

    $form['button_class'] = [
      '#type' => 'textfield',
      '#title' => t('Button class'),
      '#default_value' => $this->configuration['button_class'] ?? 'btn btn-outline-primary btn-sm btn-reset',
    ];

    $form['button_target'] = [
      '#type' => 'textfield',
      '#title' => t('Button target'),
      '#default_value' => $this->configuration['button_target'] ?? '/products',
    ];

    $form['button_icon_class'] = [
      '#type' => 'textfield',
      '#title' => t('Button icon class'),
      '#default_value' => $this->configuration['button_icon_class'] ?? 'fas fa-times',
    ];

    return $form;
  }
{@inheritdoc}