On June 30th, I received a short message from China Construction Bank saying that the loan had been issued, but no staff member contacted me later.

There should be a contract when the loan is made. The monthly repayment amount and repayment time are stipulated in the contract. If you don't have it on hand, you should ask the bank staff or real estate agent. If you don't have enough money in the repayment account before the repayment date, the responsible bank staff will inform you, but if you don't, your credit record will show bad, which is not conducive to your application for other loans in the future.