Glue for coated canvas bag

[crochetmonkey74]

A friend has asked me to customise their bag (Louis Vuitton Neverfull) with some iron on patches.
I don't think the iron on will work on the coated canvas. I tried fabric glue buy it didn't dry and the patch peeled off. How can I attach it? Sewing won't work. Should I try superglue? Any advice?

Stormsure glue from Amazon.

(Note: once opened the tube will go hard after a couple of days unless you store it on the freezer!)