This can happen with disks that are formatted as ntfs. If it's an ntfs external drive, use iboysoft ntfs for mac to gain instant write access to it on mac. Is your external hard drive showing up as read only on your mac
External Hard Drive 'Read Only' on Mac? Fix It Now! (3 Ways)
Learn how to fix a locked mac drive and get it working again.
An external drive that is read only on mac is a very common issue with proven solutions
This article is all you need to fix it. Seeing the message you can only read beneath sharing & permissions
