direnv export bash is using some bash-only syntax; specifically, ANSI C strings:
DIRENV_DIR=$'-/home/bernardo/Development/kitty'
In bash, $'...' honors escapes inside ... — so \t can be used to refer to a tab, for example. In sh, it’s not a recognized syntax feature at all.
Thus you need to run bash yourscript, not sh yourscript — or, better, start the script with a #!/usr/bin/env bash shebang, and run it with /path/to/yourscript (or just yourscript if it’s installed at a location in the PATH), letting the shebang be used to select an interpreter.
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