Are the caliper pistons in contact with anything. If there is a gap between the piston and pad, pad and disc or both then there will be no pressure.
If the pads have taken the space up and thats it try pushing them back into the caliper. This should force fluid back up the line and get things going.
Oh and the pipe. Vital. Like having a bike with no petrol.
yes you need a well fitting pipe thats VERY important, you dont want the fluid spilled on the caliper and pads!!!
Try the chemists for tube, or car accessory shop
get some help
a mate doing the nipple and tube in a jar bit
pull the lever gently until thes resistance and keep gentle pressure on
mate undoes the nipple, the lever pulls to the handlebar...keep it there
mate tightens the nipple
let the lever out fully
REPEAT until no bubbles in tube...keep level topped up
similar problem on the XJ600 and on the classic mini which i put down the the master cylinder seals collapsing, used a syringe to reverse bleed the lines from the nipple on the caliper up to the master cylinder and reinflating the seals
you should not need to have it dry.
try pulling the brakes lever back when opening the bleed screw, zip tie it back , retighten the bleed screw and leave overnight.
that should get some fluid into the MC.