error -69877 -69888 when erase disk MacBook Air

Hey sahar2580,

If you run into an error when erasing your disk, try using Disk Utility to repair the disk and then see if you can finish the process: Repair a storage device in Disk Utility on Mac - Apple Support

1. Open Disk Utility and choose View > Show All Devices
2. Select a volume, from the side pane, then click the First Aid button
3. Click Run, and follow the prompts
4. Once the process is complete, you can click Done

Start the process of erasing again and if you run into an error, see if you can capture the entire error message. That information can help us pinpoint where an issue is coming from so we can offer the best steps.

Take care.