For those who get the message (pop_os 20.04):
No such schema “org.gnome.shell.extensions.dash-to-dock”
The solution is a longer:
gsettings --schemadir ~/.local/share/gnome-shell/extensions/dash-to-dock@micxgx.gmail.com/schemas/ set org.gnome.shell.extensions.dash-to-dock scroll-action 'cycle-windows'
Explanations:
I've manually installed my dash-to-dock directly in the ~/.local/share/gnome-shell/extensions, which is where the schemas directory is located. It has to be specified explicitly.
Usage of gsettings:
gsettings [--schemadir SCHEMADIR] set SCHEMA[:PATH] KEY VALUE
Set the value of KEY to VALUE with Arguments:
SCHEMADIR A directory to search for additional schemas
SCHEMA The name of the schema
PATH The path, for relocatable schemas
KEY The key within the schema
VALUE The value to set
To list the current KEYs and their VALUEs:
gsettings --schemadir ~/.local/share/gnome-shell/extensions/dash-to-dock@micxgx.gmail.com/schemas/ list-recursively org.gnome.shell.extensions.dash-to-dock
Source of inspiration