Run the command below in a clean new directory and after a 350MB download you will dropped into a shell with the openlane flow.

docker run -it -v $(pwd):/openLANE_flow/designs/spm/runs -u $(id -u $USER):$(id -g $USER) diadatp/openlane_pdk:rc2

After that you could run the following to harden the spm design.

./flow.tcl -design spm