Here is how I did it:
1) Made new account(used just for jap eShop) using my computer (accounts.nintendo.com) and set my country of residence to Japan/my time zone to (UTC+09:00) Asia/Tokyo
2) After verification go on your switch>system settings>user>add user
3) Pick 'Sign In and Link'
4) Enter...
If your console fw is 3.0.2 I believe your switch is hackable... I'm no expert but all the info you need is in here https://gbatemp.net/threads/switch-noob-paradise-ask-questions-here.488277/
Serial: XAW100253XXXXX
Serial on device matches serial on box: Yes
Region: North America
Firmware: 3.0.1
Color option: Gray
Store: Toys R Us Canada
Was a bundle (if yes, which): Nope
Purchase date: December 28 2018
Fusée Gelée works: Yes