EFI partition is Read-Only

So I’m at the part of my usb config where I have to drag and drop the EFI folder into the partition of my USB. However, when I drag and drop the folder, instead of the green add button that appears I receive this symbol - 🚫

From further checking in terminal and the properties it says the partition is a ‘read-only file system’, even though it’s FAT32? I’ve tried nearly everything I can (including trying chmod 755 and it doesn’t give me full permissions to write to the partition). Can anyone please advise?

Thanks! :)