Hi @mousumid47477958,
Firstly key is optional and can be used to specify the encoding type. By default, Adobe Campaign uses UTF-8, but there is no harm is specifying it either.
Now, here is the magic... you should use HMACStr() instead of hmacStr() .
Sample Code:
var encodeStr = HMACStr("Adobe Campaign","UTF-8","md5");
logInfo(encodeStr);
Enjoy !
Regards,
Madhan