Extension cord recommendation for solar panel to AC200L

I recently purchased an AC200L with two 200W solar panels. The station is in a detached building in the backyard that will eventually become a home office/“chill” space. I will eventually run all the electricity (sheds been wired for lights, wall sockets, outlets, circuit breaker) off a power station/solar but for now, I am using the power station to run the wifi hotspot and portable AC unit and to keep the station charged, I need to optimize the solar input and the sunshine is just too far away from the shed.

Anyway, any recommendations for extension cord for the solar panels to the AC200L power station?