If you are trying to apply online and you are having difficulty with the Government of Canada online Access service you will have to contact an Access Customer Service Representative by phone [Monday to Friday (except Holidays) from 07:00 to 23:00 EST]:
More information about Access Key is available on the Access Key Frequently Asked Questions Web site
https://cledacces-accesskey.gc.ca/eng/fq-02.html. You can also call the Access Key Help Desk at:
Phone: 1-866-372-7742 (bilingual)
TTY: 1-866-330-1890
Outside North America: (613) 948-2888 (accepts collect calls)