How to setup vaultwarden

-- Journal begins at Fri 2023-02-24 20:33:25 CET, ends at Fri 2023-02-24 22:13:16 CET. --
Feb 24 21:32:21 DietPi systemd[1]: Starting A high performance web server and a reverse proxy server...
Feb 24 21:32:21 DietPi nginx[604]: nginx: [emerg] "upstream" directive is not allowed here in /etc/nginx/sites-dietpi/vaultwarden.conf:5
Feb 24 21:32:21 DietPi nginx[604]: nginx: configuration file /etc/nginx/nginx.conf test failed
Feb 24 21:32:21 DietPi systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE
Feb 24 21:32:21 DietPi systemd[1]: nginx.service: Failed with result 'exit-code'.
Feb 24 21:32:21 DietPi systemd[1]: Failed to start A high performance web server and a reverse proxy server.
Feb 24 22:12:17 DietPi systemd[1]: Starting A high performance web server and a reverse proxy server...
Feb 24 22:12:17 DietPi nginx[2118]: nginx: [emerg] "upstream" directive is not allowed here in /etc/nginx/sites-dietpi/vaultwarden.conf:5
Feb 24 22:12:17 DietPi nginx[2118]: nginx: configuration file /etc/nginx/nginx.conf test failed
Feb 24 22:12:17 DietPi systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE
Feb 24 22:12:17 DietPi systemd[1]: nginx.service: Failed with result 'exit-code'.
Feb 24 22:12:17 DietPi systemd[1]: Failed to start A high performance web server and a reverse proxy server.
Feb 24 22:13:16 DietPi systemd[1]: Starting A high performance web server and a reverse proxy server...
Feb 24 22:13:16 DietPi nginx[2157]: nginx: [emerg] "upstream" directive is not allowed here in /etc/nginx/sites-dietpi/vaultwarden.conf:5
Feb 24 22:13:16 DietPi nginx[2157]: nginx: configuration file /etc/nginx/nginx.conf test failed
Feb 24 22:13:16 DietPi systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE
Feb 24 22:13:16 DietPi systemd[1]: nginx.service: Failed with result 'exit-code'.
Feb 24 22:13:16 DietPi systemd[1]: Failed to start A high performance web server and a reverse proxy server.