Hello!
I'm still working with Infosys and have got PR recently. I was transferred to Canada on ICT Work Permit for 2 years. When my WP was about to expire, they initiated an extension. To file extension WP application, Infy Immigration team shared Assignment Letter along with other official supporting documents.
When I was in process to file for PR, I used those Assignment letter and supporting documents as an offer letter. Also, I requested the HR team for a reference letter in which they mentioned that I will be offered a job at least one year after getting PR status.
For you, if you got your WP extension, ask HR for reference letter. Combine all documents and attach as a job offer. It will work.