Since the system has Thunderbolt support, it is possible.  You'll want an external monitor for performance reasons (backfeeding the signal to the internal screen will appreciably hamstring the GPU performance).  Since Dell doesn't support external GPUs on this model, search around for a combination of GPU and eGPU that works with Latitude systems.  
Can i use a NVIDIA rtx 3070 as external GPU for my latitude 9420? (I need better rendering experience)
External GPU