You need to have a valid email address, applying for yourself (no family), between 18 to 54 years old, be a permanent resident of Canada, not appointing a representative, have 1,095 days or more of physical presence in Canada, and not reporting time spent as crown servant in the physical presence calculation (outside or inside Canada), those are the questions asked at the beginning and if you answer them, it will take you to the online application. You will need to accept the terms and conditions and you will be able to start filling out the application.