I suspect the ‘refind-install’ script has a [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) pointing to `/usr/bin/env`, such as

<!-- language-all: lang-none -->

    #!/usr/bin/env bash

The Recovery environment doesn't have a `/usr/bin/env`, so attempting to access that path returns the error that there's ‘no such file or directory’ there.

You can manually choose a shell to execute a script with by passing the script to the shell:

    bash ./refind-install

Alternatively, you should be able to edit the script to point directly at the shell. Replace the first line in the script with something like this, presuming the line above is what's in the file.

<pre>#!/bin/bash</pre>

Note the space has been removed.

https://apple.stackexchange.com/q/331985/37797