RITA form 37 must be printed and mailed.
SD 100 is usually e-filed, if you e-file your Ohio return. If you do not e-file the OH return (there's a $24.99 state e-file fee ), you'll also have to print, sign and mail the SD100.
Even if you do file the Ohio return, there are exceptions, to the SD100 being e-filed. So, check your Ohio filing instructions to see if you need to mail it.