SSHA512 Salting in SQL Query

I don't understand what im doing wrong.

Password = test Salt = salt

MariaDB> select to_base64(concat(sha2('testsalt', 512), 'salt'));

NmM4MzhlOTM0ZTNmZWVmYWU2Y2ZhNTNhZjExMzc1ZDQ5NTRmODVjNmY1ZWQ4ODhjMDJjZDc4MDZhNzE2OTZkMWNiNDQ5ZjJiZTc4ZTllNmVhMzAxYTk1YzgxZjI4YWQ4NzY2ZjNhZTU4MmY5YmVhYWMzM2M3ZGMyYjdiYTkxODdzYWx0

[root@host /]# doveadm pw -p test -t {SSHA512.b64}NmM4MzhlOTM0ZTNmZWVmYWU2Y2ZhNTNhZjExMzc1ZDQ5NTRmODVjNmY1ZWQ4ODhjMDJjZDc4MDZhNzE2OTZkMWNiNDQ5ZjJiZTc4ZTllNmVhMzAxYTk1YzgxZjI4YWQ4NzY2ZjNhZTU4MmY5YmVhYWMzM2M3ZGMyYjdiYTkxODdzYWx0

Fatal: reverse password verification check failed: Password mismatch

Can someone point me in the right direction? Thanks.