Why doesn't "Hello" allow me to assign ringtones to my contacts?

[AC Question]

My phone kept the ringtone for my son from a previous type phone (Windows). However, whatever version of Hello was already on the used phone I purchased (BLU Studio G 4.4.2) will not allow me to assign ringtones to my contacts with Zedge. How do I tell what version of Hello is on my phone, and is there a version that will allow me to assign ringtones? Thank you.