Hi, I'm using putty and when I try to write ü it writes | (or when I try to write é , it writes i)

I tried to change settings/translation of putty but with no success

I have KSH

# locale
LANG=
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_ALL=

could you help me with this ?