i also tried installing Uptime Kuma
as shown below
docker volume create uptime-kuma
docker run -d --restart=always -p 4381:4381 -v uptime-kuma --name uptime-kuma louislam/uptime-kuma:1
config setprop uptime-kuma status enabled TCPPort 4381 access green,red
signal-event firewall-adjust
docker network connect aqua uptime-kuma
in portainer it shows the container is running, and is joined on aqua.
but when i access the reverse proxy page, it says. 502 error also. not sure what needs to be done again.
EDIT: i got it working, here is a howto for the same: Uptme Kuma On Nethserver