Is there any way for user to contact support by email instead of direct phone call to canada support for the validation code as it expensive for us to call directly to canada.

No there is not, their phone system is overloaded as it is from what I see mentioned here, […]

Resolution for 'canada support issue: 'Registration failure on new machine' available: Yes.

The canada support issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the canada support issue yourself by looking for a resolution described in the article. If it is a complex canada support issue or you are unable to solve the issue, you may contact us by clicking here or by using other canada support support options.

For more information about resolving issues related to canada support in Quickbooks/QBO or to get support for the issue 'Registration failure on new machine', click the link below: