Bt ultafast and wifi

[squig1974]

Hi guys i have bt ultra fast 900. I have ran an ethernet cable out into my man cave and still getting fantastic speeds .my question is what can i use to get fast wifi using the ethernet cable .the bkack wifi disc isnt working 

[licquorice]

https://www.tp-link.com/uk/home-networking/access-point/tl-wa1201/