Haulix promo senders set their download and streaming permissions on a per-promo basis.  If you don't see a download button, then one of two things are happening:

1. You used up all of your allotted download attempts. If this is the case, submit a support ticket, and a Haulix team member will reset your downloads. You can also contact the respective publicist to request additional downloads.

OR

2. The promo is streaming-only. Some publicists choose not to offer downloads with their promos. To find out how a specific promo works, please contact the respective publicist and request a download.