How to extract sign text from .mca file in Minecraft?

I am writing a script that locates all the signs in my old multiplayer Minecraft world save. I want to retrieve text on these signs and store/present it somewhere.

I am leveraging anvil parser to find where signs actually are in the region’s chunk – and I get all the way up to the point where I have the sign block instance available. When I print out the properties, I get only waterlogged and rotation information.

Where is the actual text stored in the .mca file? And what would be the best way to access it give I currently have only block’s local coordinates (meaning it’s coordinates within the chunk it is located in)?

Note that this is not meant to be "looking for support for this parser I use". I know that there are people on this exchange who are familiar with .mca and nbt format, who could provide me insight into where and how to look for this kind of information. While I referenced the specific parser to give provide sufficient context, I am open to using just about any approach/technology to do this.