You must connect Hoplix to Order desk with API keys. On the Order desk page, under megage integration, search for Hoplix > Enable in your account you can generate the API by entering store name, integration and store URL > create connection. Copy the API key and Secret Key and paste them into order desk. For the integration of your choice, to connect to Hoplix, follow the information you receive from order desk.
In our Print on Demand University you can find a complete tutorial for integrating Hoplix with OrderDesk
How to integrate Hoplix with OrderDesk