How do I use an external display with a dedicated graphics card? Product: aspire 7 A715-76G

You cannot. The laptop's HDMI port is directly connected to the integrated GPU (IGPU) from the hardware side, so you cannot change or switch the connection.

This hardware-level connection means you cannot override or change the GPU routing through software settings

You should-

• Accept the hardware limitation
• Use the external monitor understanding it will be driven by integrated graphics