Smartthings and IFTTT installation while using (trial) NabuCasa

I have recently tried to set up HA on a stand-alone computer. The computer is connected to the internet via a wired connection to a Google Wifi node that again is wirelessly connected to the main node which is directly plugged into the fibre-connector.
I chose to use a trial version of NabuCasa to ease the networking/availability.
Most integrations work flawlessly, and I am able to access HA through NabuCasa from outside the house.

Whenever I try to install the Smartthings-integration it fails, and the log show that a HTTPS-connection is required. Any idea of how I proceed? I can’t find any tutorials that discuss this specific error nor any similar issues with this addon. I could always just exclude the Smartthings-hub and just use the sensors, but as I also have problems installing IFTTT it seems wiser to solve the issue at hand. IFTTT is so useful that I really want this to work.

At one point I hoped there were some flaw in the installation and deleted all to get a fresh start, and I also installed NabuCasa first thing to make sure the correct settings should be present prior to trying the IFTTT/Smartthings integrations. Still no luck.

Hope someone from the community have some experience and can direct me in the right direction!