system dependency of librsvg2-dev at Ubuntu when using R at a conda environment

I have a problem with the system dependency of librsvg2-dev at Ubuntu 22.04 when using R at a conda environment

The library librsvg2-dev is already installed and updated, but not recognized as so, when installing an R package.

I am getting the following error at an Ubuntu 22.04, when trying to install rsvg at Rstudio.

--------------------------- [ANTICONF] --------------------------------
Configuration failed to find the librsvg-2.0 library. Try installing:
deb: librsvg2-dev (Debian,Ubuntu, etc) rpm: librsvg2-devel (Fedora,
EPEL) csw: librsvg_dev, sunx11_devel (Solaris) brew: librsvg (OSX) If
librsvg-2.0 is already installed, check that 'pkg-config' is in your
PATH and PKG_CONFIG_PATH contains a librsvg-2.0.pc file. If pkg-config
is unavailable you can set INCLUDE_DIR and LIB_DIR manually via: R CMD
INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'

I have already asked at Stack Overflow, but I believe maybe this is Ubuntu-related, so I am asking here also.

This problem remind of this post, but involving a different context/error message.

The point is:

1. The library librsvg2-dev is already installed and updated;

2. From here, I understood how to check this'PKG_CONFIG_PATH'...

• The pkg-config --libs librsvg-2.0 returns:

-lrsvg-2 -lm -lgio-2.0 -lgdk_pixbuf-2.0 -lgobject-2.0 -lglib-2.0 -lcairo

Which I do not understand completely but sounds ok, as it does not return 'not fond' as in that post.

• The which pkg-config returns

/usr/bin/pkg-config

I am unable to understand the 'INCLUDE_DIR and LIB_DIR' part of the error message:

If pkg-config is unavailable you can set INCLUDE_DIR and LIB_DIR manually via: R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...

But I got from the previous outputs pkg-config is available, so, I should not try to install anything by R CMD INSTALL...

So, I assume it is related to environment. The R+RStudio is running with a conda environment. I understand the conda install x sudo apt-get issues, and I should opt for conda install librsvg2-dev as I have a conda environment, but it returns

PackagesNotFoundError: The following packages are not available from current channels:

So, I made a search at anaconda page, and I have installed two apparently related packages:

conda install -c conda-forge r-rsvg
conda install -c conda-forge librsvg

Still without success in installing rsvg...

So, I am started to think this may be Ubuntu related... But I am not an advanced Ubuntu user... and no idea about how to proceed... How can I solve it?

Is it system dependencies related because the conda environment is in use? If so, how to meet system dependencies when a conda environment is used?

Any help is appreciated.