MacBook Air 2015 Keyboard

What language is your keyboard? That info is absolutely essential to get help. Post a picture if you don't know.

For the standard English keyboard sold in the US, the right Input Source is US or ABC.

This may help

How to identify your Apple keyboard layout by country or region - Apple Support

Fohtlok wrote:

The problemen has been solved. The keyboard was portuguese.

Good news! If you have any problems making it work right , just come back here and ask.