What external hard drives can be used on 2020 macbook pro without formatting or mounting

iOS is the operating system used on iPhones. I suspect you mean macOS.

Western Digital is one source that offers drives already formatted for Macs. They will have "for Mac" in their name. One example is https://www.amazon.com/dp/B07WZYM7RQ/?th=1

khalil67 wrote:

but the last external hard drive I purchased needed to be erased, unmounted, reformatted then mounted again.

that sounds like pilot error, reformatting a drive is rather simple. please see Erase and reformat a storage device in Disk Utility on Mac - Apple Support

I do not what to have to do this. Are there any external hard drives specifically made for iOS? Thanks

when you use software from just about any manufacturer for their storage device you run the risk of that same software not being compatible with macOS updates / upgrades. it can cause the software to stop working. at best this will cause you a headache. at worst it can render your data inaccessible. it is always best to use disk utility to erase and format a drive before use to remove any preloaded software.

khalil67 wrote:

I am looking for a external hard drive to backup my macbook pro

You can use most any external drive to backup your MacBook Pro.

but the last external hard drive I purchased needed to be erased, unmounted, reformatted then mounted again.

All external drives should be reformatted before using them with your Mac.

see > Erase and reformat a storage device in Disk Utility on Mac - Apple Support

External drives mount when plugged in and they need be ejected before unplugging them.

I do not what to have to do this.

It is not an option, you must do it.

Are there any external hard drives specifically made for iOS?

Yes, but they may not be formatted correctly for the latest macOS versions.

I do not what to have to do this.

Time Machine is going to do it anyway.

You might as well get any inexpensive hard disk drive rather than one exclusively marketed to wealthy Mac owners.

There are certain operational skills every computer owner will have to employ sooner or later. One of those is external disk preparation.

You cannot escape the need to format a disk of any type for the device in question. To expect to do so, never have to format, is the same as expecting to buy an automobile that you won't have to put some kind of "fuel" in the tank, or battery, for it to run.

khalil67 wrote:

I am looking for a external hard drive to backup my macbook pro but the last external hard drive I purchased needed to be erased, unmounted, reformatted then mounted again. I do not what to have to do this. Are there any external hard drives specifically made for iOS? Thanks

It's so easy to reformat a new external "PC" drive that there is little reason to limit yourself to "Mac" drives.

As a first-order approximation,

• External PC drive = Drive pre-formatted with NTFS
• External Mac drive = The same drive pre-formatted with HFS+ (Mac OS X Extended (Journaled))

One trip to Disk Utility to erase a drive and reformat it using HFS+ or APFS is enough to make it a Mac drive. And sometimes the "PC" drives are on sale for better prices, or are easier to find.