Refrence link: https://nginx.org/en/linux_packages.html#Ubuntu

Install the prerequisites:

sudo apt install curl gnupg2 ca-certificates lsb-release ubuntu-keyring

Import an official nginx signing key so apt could verify the packages authenticity. Fetch the key:

curl https://nginx.org/keys/nginx_signing.key | gpg --dearmor \
    | sudo tee /usr/share/keyrings/nginx-archive-keyring.gpg >/dev/null

Verify that the downloaded file contains the proper key:

gpg --dry-run --quiet --no-keyring --import --import-options import-show /usr/share/keyrings/nginx-archive-keyring.gpg

The output should contain the full fingerprint 573BFD6B3D8FBC641079A6ABABF5BD827BD9BF62 as follows:

pub   rsa2048 2011-08-19 [SC] [expires: 2027-05-24]
      573BFD6B3D8FBC641079A6ABABF5BD827BD9BF62
uid                      nginx signing key <signing-key@nginx.com>

Note that the output can contain other keys used to sign the packages.
To set up the apt repository for stable nginx packages, run the following command:

echo "deb [signed-by=/usr/share/keyrings/nginx-archive-keyring.gpg] \
http://nginx.org/packages/ubuntu `lsb_release -cs` nginx" \
    | sudo tee /etc/apt/sources.list.d/nginx.list

If you would like to use mainline nginx packages, run the following command instead:

echo "deb [signed-by=/usr/share/keyrings/nginx-archive-keyring.gpg] \
http://nginx.org/packages/mainline/ubuntu `lsb_release -cs` nginx" \
    | sudo tee /etc/apt/sources.list.d/nginx.list

Set up repository pinning to prefer our packages over distribution-provided ones:

echo -e "Package: *\nPin: origin nginx.org\nPin: release o=nginx\nPin-Priority: 900\n" \
    | sudo tee /etc/apt/preferences.d/99nginx

To install nginx, run the following commands:

sudo apt update
sudo apt install nginx