I would like to know how is the claim process for allianz powerlink plan. How fast it takes for the medical claim or to proceed with the letter to continue medical treatment?

If you are talking about medical card claim, Allianz policy holder can either go to any Allianz respective panel hospital where it would be cashless, the hospital will deal with the insurance company directly.
If it's not an Allianz panel hospital, the policy holder would have to pay then claim back.
You can either contact your agent or call Allianz hotline to get the required forms and documents to submit.
Usually the general documents required would be doctor's letter, original receipt etc (or additional questionnaire to filled in by doctor depending on situation).
Once required documents and forms are submitted, the reimbursement process may still varies between case by case basis but the usual timeline would be 1-2 weeks unless there are some complications that requires more information before the reimbursement can be processed .

It depends. No complications, upon discharge the bill will be covered. No claim process required.

Best,
Jiansheng