With a https
address the module works on my system with MM v2.30.0 and v2.31.0. Does it work if you use a https
address instead a rtsp
one?
Like this:
url: ["https://www.openstreetmap.org/export/embed.html?bbox=-151.34765625000003%2C-39.77476948529546%2C142.20703125000003%2C75.00494000767517&layer=mapnik"],