Installer doesn't work correctly with the fish shell

[Pekka Enberg]

Viktor writes:

viktor@turso> curl -sSfL https://get.tur.so/install.sh | bash

Welcome to the Turso installer!

...

Downloading Linux_x86_64 ...
######################################################################## 100,0%

Installing to /home/viktor/.turso

Updating profile /home/viktor/.config/fish/config.fish
main: line 111: /home/viktor/.config/fish/config.fish: Permission denied

I'm using Nix (with home-manager) so my .config/fish/config.fish is off limits. 

Would it be possible for the installer to use something like .config/fish/conf.d/turso.fish instead?
The content of conf.d is loaded at init.