How to integrate at UCS4.4.7 a non app-center installed docker container in UCM?

I found a very good EPR-system which suits perfactly to international accounting including requirements for the German Datev based SKR04 and SKR03. With the “maintainer”: “//SEIBERT/MEDIA GmbH” image it is easy to set up on UCS4.4. I would like to have ERPNEXT included in the Univention Appcenter and asked Frappe to participate at the SUMMIT 2021. There is an active community discussion at the forum .
I have installed docker container images at a UCS4.4.7 with docker compose for frappe erpnext, mariadb and redis.

“OnBuild”: null,
“Labels”: {
“com.docker.compose.config-hash”: “8d48447a89a539186b7fbbcd04c869a4e20b8e9eb92ace50909a85f60b3cdba9”,
“com.docker.compose.container-number”: “1”,
“com.docker.compose.oneoff”: “False”,
“com.docker.compose.project”: “erpnext-docker-master”,
“com.docker.compose.project.config_files”: “docker-compose.yml”,
“com.docker.compose.project.working_dir”: “/var/lib/univention-appcenter/apps/erpnext-docker-master”,
“com.docker.compose.service”: “erpnext”,
“com.docker.compose.version”: “1.26.0”,
“maintainer”: “//SEIBERT/MEDIA GmbH

“NetworkSettings”: {
“Bridge”: “”,
“SandboxID”: “af2ea1c052edb3ae8d462be154b81b3fd371987c0d2cf40bfb83ab18201ab29a”,
“HairpinMode”: false,
“LinkLocalIPv6Address”: “”,
“LinkLocalIPv6PrefixLen”: 0,
“Ports”: {
“8080/tcp”: [
“HostIp”: “”,
“HostPort”: “8086”
“SandboxKey”: “/var/run/docker/netns/af2ea1c052ed”,
“SecondaryIPAddresses”: null,
“SecondaryIPv6Addresses”: null,
“EndpointID”: “”,
“Gateway”: “”,
“GlobalIPv6Address”: “”,
“GlobalIPv6PrefixLen”: 0,
“IPAddress”: “”,
“IPPrefixLen”: 0,
“IPv6Gateway”: “”,
“MacAddress”: “”,
“Networks”: {
“erpnext-docker-master_default”: {
“IPAMConfig”: null,
“Links”: [
“Aliases”: [
“NetworkID”: “d81063d54a9305b916ec437874642bcaee2a9d783ad02ca42c553fc2079be049”,
“EndpointID”: “fac6091b6b81fa929feae46e7fcd28e2b0ef582bd602b0097df8be194fa98a12”,
“Gateway”: “”,
“IPAddress”: “”,
“IPPrefixLen”: 16,
“IPv6Gateway”: “”,
“GlobalIPv6Address”: “”,
“GlobalIPv6PrefixLen”: 0,
“MacAddress”: “02:42:ac:17:00:02”,
“DriverOpts”: null

What do I have to do (set) f.i. in UCR to open Port 8086/tcp. I used ufw and found with ufw app list port 8086 open. But from a client computer in the default network i get on nmap request as answer that port 8086 is not open and I can not access the webinterface of the erpnext-container.

Best solution would be that I can maintain the docker installation through UCM - at least to do the configuration to access the docker master container erpnext including handling of certificates.