The website did a blog about this last year, Follow these steps to fix your broken or detached stem:
1. Cut small pieces of duct tape — about 10-12 cm. You may need a longer piece of tape for larger stems.
2. Next, hold a pencil parallel to the broken stem, lining the center of the pencil to the break. The pencil will act as a brace.
3. Then, wrap the tape around the stem and pencil. Ensure the tape is right enough so the branch does not sag but don’t make it too tight as that may damage the stem’s delicate tissues.
4. Leave the tape on for 2 to 4 weeks and keep checking the stem daily.
5. Once the plant has healed completely, gently take off the tape without damaging the stem.