As for login in, no you do not use the same site/login info from PR application- you would create a new account- if you do a quick google search- apply for Canadian citizenship- all instructions and website will pop up.
To apply for Canadian citizenship as a family with two adults and two children under 18, applicants must meet several core criteria. Adults aged 18 to 54 must fulfill the 1,095-day physical presence requirement and file taxes for the relevant three-year period. Additionally, adults in this age bracket must provide language proficiency proof, such as a CELPIP-LS (minimum CLB 4) or IELTS score, or an eligible high school or post-secondary diploma, certificate, or degree taught in English or French. If the medium of instruction is not explicitly written on the transcripts, applicants can submit an official letter on school letterhead with a signature and stamp verifying that the coursework and exams were conducted in English or French. For children under 18, the physical presence, tax filing, and language requirements do not apply, though they must apply alongside a parent or legal guardian. Also, you would need a digital photo taken by a professional photographer for the application for all 4 members and upload that as well in the application. Any previous passports you have held (even if expired) within the last 5 years eligibility and all addresses in and outside Canada last 5 years from the date the application is submitted needs to be entered as well. Website also says you will need two pcs of ID to upload- PR card can be one of them and then a drivers license/provincial health card etc as secondary. Once you create an account and start the application- you will see everything that needs to be entered. But make sure for you and your spouse there is the english requirement fulfilled along with taxes for both filed last 3 years.
