KFC informed me to apply for a health certificate. Call them when you're done and ask when it will be delivered. They told me to wait for further notice. Do I have to deliver it first?

I used to work in KFC. . Don't worry about what you said. A cashier or receptionist will inform you. Generally, a health certificate is required, and it will not be rejected without special reasons. And after living in KFC for half a year, the cost of health certificate will be reimbursed. You should keep hospital receipts or invoices or something. Then hand it in.