Your would need to follow the below steps to set up your Wi-Fi Key for a different SIM Card:

    1. Connect a PC or Laptop to the Wi-Fi Key Hotspot
    2. Open a web browser and enter (password by default is admin)
    3. Select Mobile Broadband > Connections > Account Type and select Custom.
    4. Enter the APN settings according to which SIM Card you will be using and Save.