Why can't I format this SD card with APFS on my MacBook Pro?

You need to partition the drive first, using GUID Partition Scheme. Do this in Disk Utility Then you will be able to format it as APFS. APFS requires GUID Partitioning.

The error message told you what needed to be done.

Many SD cards come come from the factory set up with MBR partition scheme and FAT32 format. APFS only works with GUID partition scheme.

awesom-o wrote:

I am trying to format an SD card and encrypt it with a password. I have done this with hard drives using disk utility without an issue, but for some reason I am running into issues making this work on this SD card.

Here are the only options I can access when erasing the disk:

https://discussions.apple.com/content/attachment/a383b9ae-c9a7-4d1c-862f-f0b15785c2df

If I format the disk as Mac OS Extended and try converting to APFS this is the error I see:

https://discussions.apple.com/content/attachment/0f870e45-3501-4a25-a6a0-388a20a42492

Is there a step that I am missing?

[Re-Titled by Moderator]

Maybe the SD card you are using has a physical lock on it.

Some SD cards have a write lock. This is a switch on the side of the card.