Apex methods can be imported inside LWC modules via the @salesforce/apex
scoped import. The method can be imperatively invoked by calling the module default import. Apex methods expect to receive its arguments as an object where each object key maps to Apex method parameter name.
This rule ensure that the Apex method receives its arguments as an object.
Example of incorrect code:
import { findContacts } from '@salesforce/apex/ContactController.findContacts';
findContacts('Ted');
findContacts('Ted', 'Salesforce');
Example of correct code:
import { findContacts } from '@salesforce/apex/ContactController.findContacts';
findContacts({ searchKey: 'Ted' });
findContacts({
searchKey: 'Ted',
company: 'Salesforce',
});