VxRail to ToR switch

Hi, this is my first post.

Someone I know got a VxRail appliance since 2017. Two weeks ago an order was placed for a switch, Dell EMC S4128F-ON as the ToR switch. The SFPs are 10G and are not compatible with the VxRail appliance.

Right now, I need an SFP to RJ45 so I can connect the VxRail to the switch. I tried a CISCO SFP, and there was no signal for the switch. 

Does this mean I can't configure that switch with a 1G SFP or I must get a Dell SFP?