Help Programming ATEMGA4809 from Arduino IDE

I recently created and completed a project to replace the processor on a PCB with an alternate. This project is complete, and I have prototype PCBs ready to receive code. But the Freelancer that completed the PCB project isn't familiar with the ATMEGA4809 processor and couldn't help me upload the Arduino IDE native code onto the new PCB. I need someone to review the schematic and walk me through exactly what to do to upload my code to the new PCB, including what hardware to buy if what I have (Sparkfun AVR Pocket Programmer) doesn't work. Ability to communicate clearly in English is required.