Just purchased this game on Steam and so far have not had a great experience trying to play the game or finding this support portal. I have a hard time reading small text and was happy to find a UI Scaling option in the menu. Unfortunately, when I turn the UI Scaling up, the main menu goes off the screen and is unusable:
Currently running at 1920x1080 but may try 720 to see if that is easier to read.
I went to the Steam discussions page to see if anyone else had this issue and found a link to a known bugs page on your website which appears to no longer exist anymore. This should probably be updated for people who use Steam to get information.
Discussion thread: Airport CEO Bug Reporting :: Airport CEO General Discussions
Link to missing page: https://www.airportceo.com/known-bugs-missing-features
Edit: You may want to check the accessibility and contrast of your tutorial font/background. This text is almost unreadable to me at that size. Increasing the font size or offering a darker background might make it easier to read.
As for the issue, I would suggest you bug report it in a smaller text in order to get the point to the Developers.