Hi @Lauren_Coker! Great question! All of the STEM Labs, Unit challenges and answer keys found in the teacher portal at education.vex.com are free!
However, you can use PD+ and this community to request specific coding solutions or any other questions you may have about the materials. This is an example of that. Accessing PD+ (including this community) is something that renews each year.
Let me know if this helps 
