liblua5.3-0 is not automatically installed.
OS
Debian 11
Purr-Data
Pd-l2ork-2.17.0 20210417-rev.ca592f6f
Installing method
"By hand" as said here.
ISSUE
Pdlua needs LUA lib to work properly. After installing purr-data, I had to install liblua5.3-0 by hand to make Purr treat *.pd_lua files as objects inside a patch.
I think that, as it is a dependency, it should be automatically installed.