Hey there!
I think I understood this correctly without google translate. 
So you want to pass on your app to a customer, correct?
Cool. First you want to make your app copyable, or cloneable, by going to settings. Flip the checkbox that looks a lot like this,
And tell your customer to click ‘copy this app’ when visiting it. When your customer has successfully copied it, you can flip that switch again - you don’t want strangers copying your app!
There’s a similar thread like this one here.
Hope this helps!