You need a Minolta AF to Sony E/NEX adapter. The MD/MC Minolta mount is different from the AF mount, so the AF lenses don't physically fit the MD-NEX adapter. 

K&F have a list of which adapter will work for each lens to camera combination they support 

Could you please update us your full Minolta lens model ?as Minolta has MD MC and AF mount, K&F Concept MD-M4/3 is suitable for: Lens: Minolta MD MC Mount lens(not for Minolta AF mount: KF06.157) Camera: Micro 4/3 (MFT) mount mirrorless camera like Olympus PEN, OM-D series, Panasonic Lumix DMC-G1, G2, G3, G10, GX1, GH1, GH2, GF1, GF2, GF3, GF5, GH4, Panasonic AG-AF100 Mirrorless Digital Cameras, Black Magic Pocket Cinema Camera (BMPCC) 

not sure about SR minolta mounts? I have fuji X mount camera, and connected a MC ROKKOR lens using a crossover adapter FOTODIOX....not a K&F. Not sure why amazon think I have K&F? I recommend fotodiox. 

MD-FX you are asking, the button you asked is a lens release button, when you want to take the lens off, you need to press this button down, hope it helps and please trust to purchase.