I booked a flight to The US through Air Canada and I am trying to check in online before the 24 hour period.

In the form they request a Canadian permanent resident card information which I don’t have because I am a British citizen & I am traveling to the US not Canada.

They wont let me bypass that question so I can’t complete the form which is a issue because I can’t check in .

Why are they asking for this information from a British citizen who’s destination is the US but is simply traveling on a canadaian airline how do they expect me to have this info?
Will it cause a issue in check in when I get to the airport ????

Please help me im really worried .