Help making munin work in ubuntu with lighttpd

I’m trying to install munin in my ubuntu VPS
I used apt install munin-node munin to install it.

But I can’t make the web interface work.
Since I already have pihole there I’m using lighttpd with this config (for the most part the default from the documentation)

server.modules += ( "mod_alias" )
server.modules += ( "mod_fastcgi" )
server.modules += ( "mod_rewrite" )

$SERVER["socket"] == ":8467" {

alias.url += ( "/munin-static" => "/etc/munin/static" )
alias.url += ( "/munin"        => "/var/cache/munin/www/" )
server.document-root = "/var/cache/munin/www/"

fastcgi.server += ("/munin-cgi/munin-cgi-graph" =>
                   (( "socket"      => "/var/run/lighttpd/munin-cgi-graph.sock",
                      "bin-path"    => "/usr/lib/munin/cgi/munin-cgi-graph",
                      "check-local" => "disable",
                   )),
                  "/munin-cgi/munin-cgi-html" =>
                   (( "socket"      => "/var/run/lighttpd/munin-cgi-html.sock",
                      "bin-path"    => "/usr/lib/munin/cgi/munin-cgi-html",
                      "check-local" => "disable",
                   ))
                 )

url.rewrite-repeat-if-not-file += (
                   "/munin/(.*)" => "/munin-cgi/munin-cgi-html/$1",
                   "/munin-cgi/munin-cgi-html$" => "/munin-cgi/munin-cgi-html/",
                   )
}

When the service is restarted it the log shows this error even when the files have 777 permissions

(gw_backend.c.1404) invalid "bin-path" => "/usr/lib/munin/cgi/munin-cgi-graph" (check that file exists, is regular file, and is executable by lighttpd)
(gw_backend.c.1404) invalid "bin-path" => "/usr/lib/munin/cgi/munin-cgi-html" (check that file exists, is regular file, and is executable by lighttpd)

When I try to run a config with the command lighttpd -D -f /etc/munin/lighttpd.conf
The output is this

(gw_backend.c.324) child exited: 1 unix:/var/run/lighttpd/munin-cgi-html.sock-3
(gw_backend.c.468) unlink /var/run/lighttpd/munin-cgi-html.sock-3 after connect failed: Connection refused
(gw_backend.c.324) child exited: 1 unix:/var/run/lighttpd/munin-cgi-graph.sock-0
(gw_backend.c.468) unlink /var/run/lighttpd/munin-cgi-graph.sock-0 after connect failed: Connection refused

Do you guys have any clue what might be happening?