file name should be fluttercoin.conf , located in a folder with chain of this coin, (usually C: drive   ...blabla...Roaming/.)
to get nodes you can go  https://www.cryptopia.co.nz/CoinInfo/?coin=FLT   , then click "Connections"  , after a second you will see a window with active nodes - so just copy&pase it into conf file, restart client, job done.

by the way, there is some short FLT video on YT: https://youtu.be/KjDOJBrMhvk