download nginx source and echo module source

wget http://nginx.org/download/nginx-1.22.1.tar.gz
wget https://github.com/openresty/echo-nginx-module/archive/refs/tags/v0.63.tar.gz

unpack

tar -xzvf nginx-1.22.1.tar.gz
tar -xzvf v0.63.tar.gz

view nginx build options

nginx -V
nginx version: nginx/1.22.1
built by gcc 7.5.0 (SUSE Linux) 
built with OpenSSL 1.1.1l  24 Aug 2021 SUSE release SUSE_OPENSSL_RELEASE (running with OpenSSL 1.1.1l  24 Aug 2021 SUSE release 150500.15.4)
TLS SNI support enabled
configure arguments: --prefix=/usr/ --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib64/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/run/nginx.pid --lock-path=/run/nginx.lock --http-client-body-temp-path=/var/lib/nginx/tmp/ --http-proxy-temp-path=/var/lib/nginx/proxy/ --http-fastcgi-temp-path=/var/lib/nginx/fastcgi/ --http-uwsgi-temp-path=/var/lib/nginx/uwsgi/ --http-scgi-temp-path=/var/lib/nginx/scgi/ --user=nginx --group=nginx --without-select_module --without-poll_module --with-threads --with-file-aio --with-ipv6 --with-http_ssl_module --with-http_v2_module --with-http_realip_module --with-http_addition_module --with-http_xslt_module=dynamic --with-http_image_filter_module=dynamic --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_auth_request_module --with-http_random_index_module --with-http_secure_link_module --with-http_degradation_module --with-http_slice_module --with-http_stub_status_module --with-http_perl_module=dynamic --with-perl=/usr/bin/perl --with-mail=dynamic --with-mail_ssl_module --with-stream=dynamic --with-stream_ssl_module --with-stream_realip_module --with-stream_ssl_preread_module --with-pcre --with-pcre-jit --with-cc-opt='-fmessage-length=0 -grecord-gcc-switches -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -g -fPIC -D_GNU_SOURCE' --with-ld-opt='-Wl,-z,relro,-z,now -pie' --with-compat

append configure options, build

./configure $(argsuments) --with-debug --add-module=/usr/local/src/echo-nginx-module-0.63 
make
sudo make install

add debug to nginx error_log directive

error_log  /var/log/nginx/error.log debug;

example of use echo in nginx config

        location /hello {
            echo "$http_test_header";
            echo "$cookie_phone";
        }