Mio's rune slot won't unlock : rEiyudenChronicle

mio slotMIO SLOTS presents $7 freeplay to new customers. One time 100% bonus on any deposit. 100% bonus on 1st deposit. 50% bonus on 2nd deposit. 40% bonus onResearch tells me that an MIO slot won't accept a PCIE card. I assume it's not possible, but i couldn't find anything definitive about a