@meso @alex Get a cert for soap.asbestos.cafe (or whatever other subdomain you want), download soapbox and unpack it into /var/www/soapbox (move files out of static/ so that index.html and the rest is in the dir), then add the following server block after the others.
server { server_name soap.asbestos.cafe; listen 443 ssl http2; listen [::]:443 ssl http2; ssl_session_timeout 1d; ssl_session_cache shared:MozSSL:10m; # about 40000 sessions ssl_session_tickets off; ssl_trusted_certificate /etc/letsencrypt/live/soap.asbestos.cafe/chain.pem; ssl_certificate /etc/letsencrypt/live/soap.asbestos.cafe/fullchain.pem; ssl_certificate_key /etc/letsencrypt/live/soap.asbestos.cafe/privkey.pem; ssl_protocols TLSv1.2 TLSv1.3; ssl_ciphers "ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4"; ssl_prefer_server_ciphers off; # In case of an old server with an OpenSSL version of 1.0.2 or below, # leave only prime256v1 or comment out the following line. ssl_ecdh_curve X25519:prime256v1:secp384r1:secp521r1; ssl_stapling on; ssl_stapling_verify on; gzip_vary on; gzip_proxied any; gzip_comp_level 6; gzip_buffers 16 8k; gzip_http_version 1.1; gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript application/activity+json application/atom+xml; # the nginx default is 1m, not enough for large media uploads client_max_body_size 90m; ignore_invalid_headers off; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_set_header Host $http_host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; root /var/www/soapbox; location / { try_files $uri /index.html =404; error_page 404 = /404.html; } location ~ ^/(activities|relay|schemas|pleroma|contexts|objects|internal|users|inbox|api|.well-known|nodeinfo|proxy|media|oauth|socket|manifest.json|favicon.png) { proxy_pass http://phoenix; } access_log /var/log/nginx/asbestos.cafe.access.log; }