Botox can migrate (spread) after injection, especially when pressure is applied. There is a risk that if this happens, you may not get your desired result. Ultimately, you should discuss your plans with your injectionist and receive clearance from them before proceeding with your massage.
After Botox you do not want a facial or massage of the treated area. If you had forehead Botox I would not want you lying prone either. Since your Botox was to the neck you should be fine with a massage but not to the neck area. My Best, Dr C
