As far as the government is concerned, you do not need to provide anything other than a health declaration to the customs (NOT the green health code).
You may be required or recommended to be tested upon arrival for public health reasons (estimation of positive rates abroad and monitoring of new variants); if you test positive, you may be transported to your domicile or hotel and be advised of ordinary precautions, but you no longer have an legal obligation to quarantine or isolate. No other consequences have been reported.
With respect to the testing "requirement", according to social media reports, most Chinese airlines basically no longer care about it. However, many foreign airlines and their ground agents (including if you are connecting to a Chinese-operated flight after a foreign segment) can be quite stricter about it and may go as far as requiring an "official" report (they would insist the home testing kit must be certified by a lab or monitored by video), even if that is explicitly not required of them. Some ground agents may be convinced by the announcement on local Chinese embassy site; some may insist on the testing requirement.
The advice floating on social media is to have a backup report, including suggestions to use digitally modified reports, but that may be illegal.