Custom Sha1 hash type

[someuser1]

Thank you for your answer but I cant seem to understand it.

How can I run hashcat with that type of hash?

Let's assume my username is "admin" salt is "1234" and password is "1".
sha1(salt.password)=a3abfb32023fc352e71e3a487b66fe9f094a1e1a
sha1(salt.username.password)=9635a2f6891d42082e81f38716180e5d283f0a5d