Enclose the whole code block with two “triple tics” (i.e., ```) lines.
It is the a Markdown markup-language dialect, Markdown is well documented at many places.
The LVM layout is exactly the same as for a Xperia model with 64 GB internal FLASH memory, hence you might use these values for resizing the root and home volumes.
Does that mean, “it is a Gigaset GS290-based Volla phone”?
BTW, I researched what the Volla 22 is, which hardware does the Volla X you mentioned use?
You have to fastboot that recovery image (step 4 above), as Jolla describes it for the Xperias.