I think you will need eTA ahead. This can be done by raising a web form. You will need to attach the PHAC report and in the text need to add covid-19 to flag it.
Here in my country, we request the statement of marks to university... They will attest and seal it...
We can get N number of such copies...
Not sure why u sent original copy...
Anyways they should return it.. contact them
Transcripts wont hold any value, if the envelope is open..
Iqas would have definitely opened it right ..
And that's not as such original... It's attested document in a way...