Not found errors

[BlazyDoesDev]

E: Failed to fetch http://deb.debian.org/debian/dists/stretch/main/binary-amd64/Packages 404 Not Found E: Failed to fetch http://deb.debian.org/debian/dists/stretch-updates/main/binary-amd64/Packages 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead. The command '/bin/sh -c apt-get update && apt-get install -y curl debian-keyring debian-archive-keyring apt-transport-https nginx' returned a non-zero code: 100