In Networking > Templates, you can upload the .vma file of a virtual network device. To upload a template file, click Upload, select the vma file that you want to upload, and specify datastore. Then click Upload to start upload

If the template file is uploaded successfully, you will see its information in the template list, as shown below:

To create a virtual network device, drag the virtual network device onto the canvas and configure the basic information, then click Apply Changes.