glue on(to) (something)
To use glue to adhere something to something else. When "on" is used, a noun or pronoun can be used between "glue" and "on." Have you glued those pictures onto the poster yet? No, it's fine, I'll glue the lace on.
glue something on(to) something
and glue something to something; glue something onto attach something to something else with cement. Please glue the binding onto this book. Someone pulled it off. Please glue on the binding.