How can I use rEFInd boot manager without an enter key? I have a MacBook Air (11-inch, Late 2010) (it’s old I know) and I have installed rEFInd on an USB. The thing is, my return key does not work, so rEFInd is basically useless. Is there any way rEFInd can be configured to be used without the return key.
You can try using one of the following:

rEFInd does have the ability to work will a mouse. If this does not work automatically, then you may have to edit the refind.conf file. This file can be found in the EFI/BOOT folder of the EFI volume labeled ElTorito on the USB.
By default, you can make your selection by pressing a number key. So for example, if the first row on the displayed rEFInd menu has three icons, the you can make a selection by pressing either the 1, 2 or 3 key. In fact, you can do this before the menu is even displayed.
The return key has the ASCII code of 13, which is a control M. So you can substitute pressing the control+M key combination for pressing the return key.