npm run build issue

[Gauthierch]

Hello everyone,
This is probably a noob question. When i type:
npm run build
I got this :

firestoremigrate@0.3.0 build C:\Users\gogv\Desktop\firestore-migrator-master
tsc

And then the terminal reload, nothing else happen and i'm no able to launch a fire-migrate command.. (command not found)

Could you let me know what I'm supposed to do ?
Thank you in advance

Have a nice day

[Gauthierch]

Answers to me : npm run migrate export/import ......