Need Advice on extending Orbi Wifi

Hi... I have an Orbi RBR850 with 4 RBS850 in my home, but I need to extend to my shed, but the current wifi signal does not reach although one of the Orbi's is placed as close to the shed as possible without being outside. I do have cat6 cable running to the shed. So am wondering on best solution to extend the same WiFi over to the shed...can I do this with another RBS850, or RBR850? or is there an outside extender I could utilise to get the signal over to the shed? Needs to be same wifi network for security cameras to work properly. Appreciate any advice.