It is in the FAQ in more deal. Looks like they left out 'in' in the second question as they are both the same question -- I sent them an email on it.Before anyone else goes and does the research like I did...
This HSA is only offered to folks with a high-deductible health plan.
About half-way down this page, they define HDHPs:
...
Many folks on here have HDHPs, I'm sure. Mine doesn't meet the requirement, however.
https://www.fidelity.com/go/hsa/faqs