% !TeX program = LuaTeX
\nopagenumbers
% load package and store it in a global Lua variable
\directlua{barracuda = require "barracuda"}
\newbox\mybox

ISSN test:

\vskip10pt
\leavevmode
\directlua{barracuda:hbox("ean-issn", "9778881543480", "mybox")}
\box\mybox

\vskip10pt
\leavevmode
\directlua{barracuda:hbox("ean-issn+5", "977888154348000028", "mybox")}
\box\mybox

\vskip10pt
\leavevmode
\directlua{
local ars_issn = {
    online  = "9771828236001",
    print = "9771828235004",
}

barracuda:hbox("ean-issn+5", ars_issn.online.."00028", "mybox")
}
\box\mybox

\vskip10pt
\leavevmode
\directlua{
local barcode = barracuda:barcode()
barcode:set_param("debug_bbox_on", true)
barracuda:hbox("ean-issn", "1828-2350", "mybox")
}
\box\mybox

\vskip10pt
\leavevmode
\directlua{
barracuda:hbox("ean-issn+2", "1828-2350 [01] 22", "mybox")
barracuda:save("ean-issn+2", "1828-2350 [01] 22", "ars")
}
\box\mybox

\vskip10pt
\leavevmode
\directlua{barracuda:hbox("ean-issn", "1828-2350 [01]", "mybox")}
\box\mybox

\vskip10pt
\leavevmode
\directlua{barracuda:hbox("ean-issn+5", "1828-2350 [01] 00028", "mybox")}
\box\mybox

\bye