it is the encrypted form like with useradd(8)
More than one way to do it, depends on the hashing algo being used/set-up on the target system and salt being used or not
one way is to use openssl passwd
one is to copy the encrypted string from a shadow file
reading the follwing can help:
http://serverfault.com/questions/330069/how-to-create-an-sha-512-hashed-password-for-shadow
Phil.