Does anyone know where I can enter a licence key ?
Would i need to re-download the app?
Hi there @Jinx_Cat! Thanks for reaching out to us about this, this page should help: https://balsamiq.com/wireframes/desktop/docs/intro/#registering-balsamiq-wireframes-for-desktop
You can reach us at sales@balsamiq.com if you still have any problems registering 
Best,
Kendra