https://www.canada.ca/en/revenue-agency/services/e-services/e-services-individuals/netfile-overview/eligibility.html
SIN starts with 8 or 9 can not register with CRA.
Other restrictions
The following is a list of specific situations that prevent you from filing a tax return through the NETFILE service:
Your tax return was discounted by a third party
You are considered a deemed resident (that is, you don’t have to pay provincial or territorial tax)
You are filing a tax return for an individual who died in 2019 or 2020
Your social insurance number or individual tax number begins with 08 or 09