Understanding WSUS Client Configuration

[Machine A] (WSUS server)
Windows server 2016 (Domain Controller)
domain:samba.ubis.local
addresses:192.168.1.15
[Machine B] (Client)
Windows 10
domain:PC08.ubis.local
Address: 192.168.1.20

After we built WSUS on machine A, we made machine B join the same domain, enabled the group policy "Specify Microsoft Update Service Location on Intranet" on machine B, entered the WSUS address "http://samba.ubis.local:8530" and updated the group policy with "gupdate/force". Machine A and machine B can ping each other and resolve the name with nslookup.
How can I add machine B?Please let me know.