upload = vk_api.VkUpload(vk)
photo = upload.photo_messages('вашфайл')
owner_id = photo[0]['owner_id']
photo_id = photo[0]['id']
access_key = photo[0]['access_key']
attachment = f'photo{owner_id}_{photo_id}_{access_key}'
vk.messages.send(peer_id=event.object.peer_id, random_id=0, attachment=attachment)