On Linux, set up the Vivado environment in a terminal window by sourcing <Vivado_install_path>/settings64.sh.
To build the Vivado project using the provided Makefile, type the following in the $REPO_SRC directory:
make build_hw
The result of this operation will be an XSA file in output/scu35-prod-base/reference_images/environmental_monitoring.xsa which will be used by vitis in the software section.
To see more Makefile options:
make help