code: public function usageCharge(StoreUsageCharge $request)
      {
          // Activate and save the usage charge
          $validated = $request->validated();
          $uc = new UsageCharge(ShopifyApp::shop(), $validated);
          $uc->activate();
          $uc->save();
  
          // All done, return with success
          return isset($validated['redirect']) ?
              Redirect::to($validated['redirect'])->with('success', 'usage_charge') :
              Redirect::back()->with('success', 'usage_charge');
      }
docs: Allows for setting a usage charge.
  
  @param \OhMyBrew\ShopifyApp\Requests\StoreUsageCharge $request
  
  @return \Illuminate\Http\RedirectResponse