How to fix N: Skipping acquire of configured file 'nginx/binary-i386/Packages' as repository 'http://nginx.org/packages/ubuntu bionic InRelease' doesn't support architecture 'i386'

I have installed latest nginx stable with this tutorial http://nginx.org/en/linux_packages.html (Ubuntu section), but every time i update packages with apt update i always got this error doesn't support architecture 'i386'

Full error :

N: Skipping acquire of configured file 'nginx/binary-i386/Packages' as repository 'http://nginx.org/packages/ubuntu bionic InRelease' doesn't support architecture 'i386'

I get this error when i running :

apt-get update

How to solve this error :

Edit /etc/apt/sources.list.d/nginx.list

Change :

deb [signed-by=/usr/share/keyrings/nginx-archive-keyring.gpg] http://nginx.org/packages/ubuntu bionic nginx

To this :

deb [arch=amd64 signed-by=/usr/share/keyrings/nginx-archive-keyring.gpg] http://nginx.org/packages/ubuntu bionic nginx

Edit arch= with your machine architecture, in my case, i use amd64 KVM Ubuntu template so arch=amd64.