To make it work you should copy the .env.sample file with cp .env.sample .envand put here your Nordigen keys:
export NORDIGEN_SECRET_ID= YOUR_SECRET_ID
export NORDIGEN_SECRET_KEY= YOUR_SECRET_KEY
After that run source .env
Now you can run sbt run or even better:
sbt and after you are prompted into the console you should run:
~reStart this will give you the hot-reload feature