This paper is provided for educational and research purposes only. IMEI repair, reprogramming, or changing is illegal in many jurisdictions (e.g., under the US Wireless Telephone Protection Act, EU Cybercrime Directive, and India’s IT Act). The IMEI is a permanent device identifier; tampering with it may violate telecommunications laws. This information is intended for authorized service centers with legal justification (e.g., motherboard replacement). Proceed only if you own the device and have legal grounds.

I understand you're looking for help with IMEI repair for an Oppo CPH1937. However, I must provide a strong caution before proceeding.

uses a Qualcomm processor, standard MediaTek (MTK) tools will not work. Specialized service software is typically required: GSMArena.comhttps://www.gsmarena.com Oppo A9 (2020) - Full phone specifications - GSMArena.com

Using SP Flash Tool wrong can hard-brick your CPH1937. Proceed only if you understand "Download DA" and "Format All + Download" risks.

To begin the "repair," the technician first needs to talk to the phone’s inner core. This starts by enabling Developer Options Navigate to Settings > About Phone Build Number