Need swap on Leap 15.4 on /dev/sdb

I need a swap on /dev/sdb4. Can i convert it to extended partition, add a swap(& maybe a /home) and keep the rest intact?

Due to the 2 Windows partitions I couldn’t create a swap, and found later I need one.

I have another post trying to explain why there are 2 Windows items in the Grub menu. THAT is what kept me from making a swap a partition.
And I wasn’t smart enough at the time to try an extended partition to put Leap on with Swap, root,and possibly a /home partition.

sdb      8:16   0 465.8G  0 disk 
├─sdb1   8:17   0   100M  0 part **<<<< WINDOWS reserve**
├─sdb2   8:18   0   500M  0 part **<--------LEAP boot partition
├─sdb3   8:19   0 212.4G  0 part **<<<< Windows 7**
└─sdb4   8:20   0 252.7G  0 part **<--------Leap / partition.**

fdisk -l /dev/sdb
Disk /dev/sdb: 465.76 GiB, 500107862016 bytes, 976773168 sectors
Disk model: ST500NM0011     
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000001

Device     Boot     Start       End   Sectors   Size Id Type
/dev/sdb1  *           64    204863    204800   100M  7 HPFS/NTFS/exFAT   **<<<< WINDOWS reserve**

/dev/sdb2          206848   1230847   1024000   500M 83 Linux **<--------LEAP boot partition
/dev/sdb3       531282528 976769071 445486544 212.4G  7 HPFS/NTFS/exFAT    **<<<< Windows 7**

/dev/sdb4         1230848 531282527 530051680 252.7G 83 Linux **<--------Leap / partition.**

Partition table entries are not in disk order.

You could try fixparts, but I would not hold my breath. If it refuses, you can always add swap file on your linux filesystem.

Thanks for the response.
BUT! forget it, doesn’t matter now, I somehow managed to screw up Leap 15.4 on /dev/sdb .
Others in here could/will tell you that I tend to do stupid things!
But, it WILL give me a chance to reinstall, and set up an extended partition first.