Gmt text command gives me error for offseting text

I am using GMT 6.3 on a linux Ubuntu machine
gmt text command gives me an error when I add the offset option.
This is my line of script:
echo 86.539W 12.423N Momotombo | gmt text -F+f10p,Helvetica-Bold+jCB -D1c,-2c

This is the error message:
text [WARNING]: 1c,-2 not a valid number and may not be decoded properly.

If I remove the -D option it works but obviously doesn’t offset the text

Any help on how to solve this?
Thanks in advance

There is no dx ,dy only dx/dy.

Thank you for the clarification. It does work now