gio:simple-action-group-lookup (group name)

group -- a g:simple-action-group instance
name -- a string with the name of an action

The g:action instance, or nil.

Looks up the action with the name name in the action group. If no such action exists, returns nil. The g:simple-action-group-lookup function has been deprecated since version 2.38 and should not be used in newly written code. Use the g:action-map-lookup-action function.