Create Raspberry Pi Image using a Raspberry Pi
My 2019 Macbook Pro w/Catalina 10.15.6 will not write to micro sd cards with any of the adapters I have available.
They appear as "read only". OSX Disk Utility app will not format the SD cards. Error is
Couldn't modify partition map. : (-69874)
To get around this, I used a Raspberry Pi to download the image and write it to the micro SD card.
I used a usb micro SD card reader from Canakit https://www.canakit.com/mini-micro-sd-usb-reader.html. I inserted the USB/SD reader after the Pi booted.
For this example, I'm using an Ubuntu image. This will likely work for other Raspberry Pi images.