Defaulting G/L account in work order settlement rule

Hello,

I have set my work order settlement profile, the default object to be G/L. However, in the equipment master record, at the Organization tab (account assignment group), i don't see any field for G/L account.

When i create settlement rule with default, i get error that rule cannot be created with default.

Where can i enter the G/L account in the equipment master to enable the auto settlement rule creation?