I have an external 1TB Seagate Harddrive but it shows that only 268MB is available. Why?
I found a solution to this problem. I had to first attach the hard-drive to Windows 10 and delete the last two volumes in /dev/disk6 (DOS_FAT_32 &quot;FV&quot; and Linux) through Windows disk management. After that I attached it back to the Mac and via disk utility erased it one more time with structure APFS.

/dev/disk0 (internal):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                         500.3 GB   disk0
   1:             Apple_APFS_ISC ⁨⁩                        524.3 MB   disk0s1
   2:                 Apple_APFS ⁨Container disk3⁩         494.4 GB   disk0s2
   3:        Apple_APFS_Recovery ⁨⁩                        5.4 GB     disk0s3

/dev/disk3 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +494.4 GB   disk3
                                 Physical Store disk0s2
   1:                APFS Volume ⁨Macintosh HD⁩            15.1 GB    disk3s1
   2:              APFS Snapshot ⁨com.apple.os.update-...⁩ 15.1 GB    disk3s1s1
   3:                APFS Volume ⁨Preboot⁩                 439.1 MB   disk3s2
   4:                APFS Volume ⁨Recovery⁩                1.0 GB     disk3s3
   5:                APFS Volume ⁨Data⁩                    231.7 GB   disk3s5
   6:                APFS Volume ⁨VM⁩                      20.5 KB    disk3s6

/dev/disk4 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk4
   1:                        EFI ⁨EFI⁩                     209.7 MB   disk4s1
   2:                 Apple_APFS ⁨Container disk5⁩         1000.0 GB  disk4s2

/dev/disk5 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +1000.0 GB  disk5
                                 Physical Store disk4s2
   1:                APFS Volume ⁨Naamloos⁩                1.2 MB     disk5s1