David Nebenzahl wrote:

As others have pointed out, that's a weak way to attach anything to
stucco. After all, it's at best about 1/2" thick. Just use screws long
enough to bite into the wall sheathing (plywood or 3/4" boards).

Unfortunately that only works if there is OSB or plywood as sheathing. In a
non-stress location, it could likely be fiberboard behind the stucco that won't
hold a screw.