I enlarged the base from the original 2mm to 4.75mm. This solved adhesion issues for me and made it a closer match to the stud mount I had.

You'll need a set of studs/posts to attach the roses to. I used 4mm with a drop of super glue and they've held up great.
I bought a kit a while back with several different sizes/colors (https://www.amazon.com/gp/product/B08GY16JNR) but really anything should work.