Misleading details: This add-on has a LIMITED bandwidth of 1 GB per day. After that, your account gets blocked for 1 day. You also get many notifications in order to upgrade your account to a premium one:

Dear vpn user,

we had to block your account '[...]'
temporarily because of over-usage of your free account. Our accounts are free
until a certain daily limit, then your account will be blocked until next day.
This way we plan to give fair free service for all our clients.

Your account will be enabled 2020-Feb-19 [...] GMT (London Time)
automatically from our system. You will receive sepearate email about releasing
your account. You can start using your account tomorrow at this time again.

You have generated 1870 MB traffic but at this time you are allowed to make
maximum 1000 MB.

Premium accounts are allowed to drive unlimited traffic. You might consider
upgrading your account to Premium.

Warning: you are not allowed to have multiple accounts per user based on our
Terms and Services.

2020-Feb-18