External HDD wont format Mac os 13

Make sure to select the physical drive when you erase it. Within Disk Utility you may need to click "View" and select "Show All Devices" so that the physical drive appears on the left pane of Disk Utility. The physical drive will be identified by the make & model, but with external drives, it may instead be identified by the make & model of the adapter/dock/enclosure or the chipset used by one of those items. Make sure to erase the physical drive as "GUID Partition" and whatever file system is appropriate for how you are using the drive.

Possible file systems:

• MacOS Extended (Journaled) -- if also being used by older versions of macOS 10.12 and earlier
• APFS (top option) -- if will only be used with macOS 10.13+, or if this drive will be used for Time Machine backups for macOS 11.x+
• exFAT -- if you need to share the drive with a Windows PC

Do you have a Windows or Linux PC? If so, then see if you can partition & format the drive on it (maybe even try another Mac). Sometimes a drive's partition table can get into a state where Disk Utility won't work with it. Using another OS to destroy and create a new partition table can fix the problem so macOS & Disk Utility will work with it again. It is possible to use the command line on macOS to destroy the existing partition table, but this can be risky & tricky if a person is not familiar with the command line as there are no safety nets when using the command line.

If you are going to get rid of the drive, then you can use that Windows computer to attempt to write zeroes to the whole physical drive to destroy all traces of the data on it...assuming the drive hasn't failed to the point where this won't work. You could also do this with the macOS command line, but like I said it is risky & tricky...much better to use Windows to do it if you have access to a Windows system. Or you can take a sledge hammer to the drive or even use a drill to put holes through the platters of the hard drive.

It may be possible to check the health of the hard drive, but some chipsets used by external drives, docks, and adapters can prevent access to the drive's health information. On macOS you can attempt to use DriveDx, but this will require installing a special USB driver since macOS does not natively support the necessary communication to access a USB drive's health information (again, no guarantee since the drive enclosure/dock/adapter may not allow the necessary communication even with the special USB driver). With Windows or Linux you can use GSmartControl to check the health of an external drive (no special driver needed), plus on Windows there is portable version of the app which does not require installation. Post the complete DriveDx or GSmartControl text report here using the "Additional Text" icon which looks like a piece of paper.

You also should not overlook that the cable may be defective or not fully seated.

Of course there is a chance the accidental disconnect damaged the drive heads and/or disk platters and the drive is now unusable.