If you install the snap version of Wekan, probably you'll need to setup it for your IP and port. Just follow these steps:
costales@ubuntu:~$ sudo snap set wekan-ondra root-url=”https://<your_ip>:<your_port>”
costales@ubuntu:~$ sudo snap set wekan-ondra port=”<your_port>”
costales@ubuntu:~$ sudo systemctl restart snap.wekan-ondra.wekan
If it's not working, probably you'll use the mongodb port for another app, then, change it too:
costales@ubuntu:~$ sudosnap set wekan-ondra mongodb-port=27019
costales@ubuntu:~$ sudo snap disable wekan-ondra && snap enable wekan-ondra
Now visit in the web browser https://<your_ip>:<your_port>