Need a easy guide to install a OS onto Rockpi 4b+ emmc

I am very new to Rockpi. I just want an easy guide on how to install Twister OS or OS onto my Emmc. (soldered) . I have been going through the website RADXA rockpi etc it has been very confusing. I feel the information is not straight forward.
I did MASKROM rkdevelopment tool …download OK. I tried to boot… nothing. black screen. I feel there is something missing.

I just want a easy guide for rockpi 4B+ to install OS onto Emmc… thank you

Boot it from sd-card.
Open armbian-config in a terminal
sudo armbian-config

System -> Install -> eMMC

Thank you for your reply NicoD. I tried your method. I have partitions. ext 4, ext 3, ext 2, f2fs and btrfs.
I have tried to install on ext 4, ext 3 etc. I get a message on all… partition too small. need a big size… I have a 32gb emmc.

I have been trying all day… different methods from the forum of what I read…

Please could you help.

thanks. btw i enjoy watching your youtube videos… keep up the great interesting videos.

I don’t know for sure whether the problem might be that you did the install to an SD card that is > 32GB, but I was able with a much larger SD card to install to the SD, boot the SD then download and install the OS again, while running from the SD. Takes that extra step, or you could just copy the OS install to the SD file system so you wouldn’t have to download again.