Configure speed dial for your Grandstream IP phone :
Step 1 : Locate your IP phone's IP address by pressing on "NextScr" button as shown in picture below, or refer to
https://youtube.com/shorts/ffe_53SS3P0?feature=share
Step 2 : Access to your IP phone's GUI via the IP address and navigate to Settings > Programmable Keys > Programmable Keys
Step 3 : Under "Multi-Purpose Keys" change the mode method to "Speed Dial" and key in the extension number or phone number you want to call when the speed dial button is pressed.
Note : For certain phone model, you may assign speed dial function even if there aren't speed dial button avaible. Instead of having multiple speed dial buttons, you only entitle to have one.