Gogo, the WiFi provider for airlines like Air Canada, is not available to Linux users even though it advertises "access using any Wi-Fi enabled laptop, tablet or smartphone". It is however possible to work-around this restriction by faking your browser user agent.

I tried the User-Agent Switcher for Chrome extension on Chrome and Brave but it didn't work for some reason.

What did work was using Firefox and adding the following prefs in about:config to spoof its user agent to Chrome for Windows:

general.useragent.override=Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36
general.useragent.updates.enabled=false
privacy.resistFingerprinting=false

The last two prefs are necessary in order for the hidden general.useragent.override pref to not be ignored.

Opt out of mandatory arbitration

As an aside, the Gogo terms of service automatically enroll you into mandatory arbitration unless you opt out by sending an email to customercare@gogoair.com within 30 days of using their service.

You may want to create an email template for this so that you can fire off a quick email to them as soon as you connect. I will probably write a script for it next time I use this service.