So it sounds like you are looking for what is essentially a help desk ticket generator.
Why reinvent the wheel?
Look at desk.com, part of salesforce so likely already meets regulatory requirements for things like HIPPA.
Or Zendesk.
In terms of cost I’d tell them you are a non profit that services veterans.
Providing the software at reduced or free is a write off for them and great
PR.
I strongly advocate looking into an existing solution.
I always cringe a bit when people turn to tech in an attempt to modify others behavior.
Often does not work out. I call it the biological factor. Easiest analogy, you can lead a horse to water......
It’s mostly due to, whose problem are you trying to solve, yours or theirs?
If it’s your problem then adoption will be low.
Put another way, you are offering them a solution to a problem that they don’t know even exists.
And because of that they need to have a great user experience from day one.
If it’s buggy, lacks features and does not provide perceived value to the user it will die on the vine.