You can’t just enable your hotspot trial. You are missing a huge important piece to get it to work. You must have the donor VIN from the TCU vehicle to make it work and you can only set this up online through their website with that VIN. You cannot set the trial up via the APIM. If you have access to this than you have access to the Hotspot settings.
Actually, just need to update the APIM firmware to MY18.5+ for the Hotspot menu. Also, if you use a third-party app to authenticate the TCU your account will likely be locked.