Get Unity Personal for Free

Register on Nintendo Developer site

Open https://developer.nintendo.com/register/create

Fill the fields

Then

And click on the Review Application. After click on the Submit Application.

As a result you will see

After that you will receive two emails

Open the link from the first and get your password

Then click on Menu and click on Sign In

After login, scroll to the bottom of the page, check the box to agree with NDA and click Submit

Now open https://developer.nintendo.com/group/development/developer-support

Click on Downloads in Nintendo 3DS section

Scroll to Unity for N3DS and clock on View details

Now you can get your Unit Personal free key