How to partition SSD and HDD

Hello. I have one question. I can’t find anything similar to this or maybe I can’t find it.
Thorugh the installation USB I want to know how to partition my SSD (128 GB) to have only the OS on it and the rest on my HDD (1 TB). I tried already but only my SSD was visible after the installation, no sign of the HDD. No need for dual boot, I want only Manjaro installed.
Thanks for the help.

I believe automated partitioning focus on a single drive. You may need to use manual partitioning in order to select partitions from multiple drives.

Although if you used a mount point outside of /mnt or /media for your extra drive, that drive will actually be used without showing explicitly in your file browser.
For instance, see below how my partitions are mounted across my drives. In Thunar (Xfce’s file manager), sdc2 doesn’t show up explicitly, while sda1 and sdb1 do (respectively as “backup” and “games”).

$ lsblk
sda      8:0    0   3,6T  0 disk 
└─sda1   8:1    0   3,6T  0 part /media/backup
sdb      8:16   0 232,9G  0 disk 
├─sdb1   8:17   0   184G  0 part /media/games
└─sdb2   8:18   0  48,9G  0 part /
sdc      8:32   0   1,8T  0 disk 
├─sdc1   8:33   0     4G  0 part 
└─sdc2   8:34   0   1,8T  0 part /home
sr0     11:0    1  1024M  0 rom