$ wget http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.4p1.tar.gz
$ tar xvf openssh-8.4p1.tar.gz
$ cd openssh-8.4p1
$ mkdir build
$ cd build
$ ../configure --prefix=/opt/openssh/8.4p1 --with-zlib=/opt/zlib/1.2.11/ --with-ssl-dir=/opt/openssl/1.1.1i/ --without-openssl-header-check --with-privsep-path=/opt/openssh/8.4p1/var/empty --with-pid-dir=/opt/openssh/8.4p1/var/run
$ make
$ make install