The video indicates the installation of HP Deskjet 3050 printer driver on Mac. I meant to download the driver directly from HP official website http://support.hp.com. However it moved to 123.hp.com to download a software kit named HP EASY START.
The following guide is from the HP EASY START.
Selecting a Device
If your device is powered on and already connected to your Mac over a local network, or USB cable, then it should be listed and available for selection. A new HP device should also appear in the list if you have just powered it on and your Mac Wi-Fi is on. If your device does not appear in the list then review the following troubleshooting suggestions.
If you want to connect a new device to your wireless network
Confirm that an Ethernet cable is not attached to the device as this will disable wireless setup.
Make sure the device is in HP Auto Wireless Connect setup mode. To check that your device is in HP Auto Wireless Connect setup mode, press the Wireless button on the device’s control panel display (if available) or for printers, print the Information Page, and confirm that the device’s network name (SSID) starts with “HP-Setup”.
If your device is not in HP Auto Wireless Connect setup mode and you are sure that you want to connect this device to your wireless network, then locate and select “Restore Network Settings” on the device’s control panel display.
If you are still having trouble with setup from this application, you may need to connect your device using the Wireless Setup Wizard from the device’s control panel display (if available).
1. Press the Wireless button on your device’s control panel display.
2. Select Settings from the options presented.
3. Select Wireless Setup Wizard and follow the on-screen instructions.
If a control panel setup is not an option for your device, an alternate wireless setup method will be offered.
For more information online, visit www.hp.com/go/wirelessprinting.
If you want to connect using a USB cable
Check that the USB cable is securely connected to the USB ports on the device and your Mac. If still not working, try unplugging the USB cable, wait a few moments, and then re-connect.
If you want to connect over an established wired or wireless network
For wired connections, check that the Ethernet cables are securely connected to the Ethernet ports on the device and your Mac. Also check that the device and your Mac are connected to the the same network.
Bonjour advertisement is used to discover devices on the local network. If your device is not on the same local network as your Mac, or if Bonjour advertisement has been disabled by your network administrator, then you may need to locate your device using an IP address or host name. You may find this information in the Network Settings on the device’s control panel, or for printers, by printing a network test page.