AP-BGZ as per FR24 has been parked at the international concourse of the airport, perhaps indicative of it being ready/scheduled for flights? I think it's going to fly the Toronto flight today.
On March 21, PIA Boeing 777-200LR registration AP-BGZ landed in Karachi as Jeddah to Islamabad flight PK742. The aircraft is on the ground at Karachi Airport since then.