Entering the sudo password before guix pull when updating the system

[Oleander via]

How can I enter the sudo password before `guix pull` runs when updating with 
`guix pull && sudo guix system reconfigure config.scm`?

`sudo sh -c "su -c 'guix pull' $USER && guix system reconfigure config.scm"` 
returns:

"hint: After setting PATH, run hash guix to make sure your shell refers to 
/home/user/.config/guix/current/bin/guix"

Thank you!