U2F security key/USB-Stick-For every app its own?
Have sucessfully established my Fido U2F-security-key-stick on Win10s/edge netbook. dont remember which app but not FB.
I am now on old SSE-winxp pc to setup U2F for FB. its telling to push the button or click on button(where?)when light is blinking. its on but not blinking. its on MOBOs USB-slot. last time-other app PC at least reacted by rejecting. winxp seem not working. authentication app on smartphone is enough. at one moment(too long pushing?) the light went off.