this.$refs[formName].resetFields is not a function

This error message can occur in Vue.js when attempting to reset the fields of a form using the resetFields() function on a ref to the form, but the function is not recognized as a valid method.

There are a few potential reasons why this error might occur:

1. The formName ref is not correctly defined or does not reference the intended form component.
2. The form component does not have the required dependencies imported or properly installed.
3. The resetFields() function is not supported by the version of Vue.js or the specific form library being used.

To resolve this error, try the following steps:

1. Verify that the formName ref is correctly defined and references the intended form component.
2. Check that the required dependencies for the form component, such as Vuetify or ElementUI, are properly installed and imported.
3. If the resetFields() function is not supported, try using an alternative method to reset the form fields, such as manually setting each field to its default value or using a different form library.