PostfixAdmin on Nginx returning 403 Forbidden

I haven't used PostfixAdmin in a while. When I recently went to mail.domain.com/postfixadmin I was greeted with a message telling me to point an alias to /postfixadmin/public. After a bit of searching online, this is what I changed my Nginx configuration to:

server {
    if ($host = mail.domain.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    listen 80;
    server_name mail.domain.com;

    include snippets/letsencrypt.conf;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    server_name mail.domain.com;
    root /var/www;
    ssl_certificate /etc/letsencrypt/live/domain.com-0002/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/domain.com-0002/privkey.pem; # managed by Certbot
    ssl_trusted_certificate /etc/letsencrypt/live/domain.com/chain.pem;
    include snippets/ssl.conf;
    include snippets/letsencrypt.conf;

    location / {
        try_files $uri $uri/ /index.php;
    }
    location /postfixadmin {
        alias /var/www/postfixadmin/public;
        try_files $uri $uri/ /index.php;
    }
    location /rspamd {
        proxy_pass http://127.0.0.1:11334;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
    location ~* \.php$ {
        fastcgi_split_path_info ^(.+?\.php)(/.*)$;
        if (!-f $document_root$fastcgi_script_name) {return 404;}
        fastcgi_pass  unix:/run/php/php7.4-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME 
        $document_root$fastcgi_script_name;
    }
}

Now I get an 403 Forbidden error trying to access PostfixAdmin. I assume my configuration is wrong somewhere?