To get the value of a field use getFieldValue. Returns the value as a string.
formsApi.getFieldValue(fieldName)
In the case of multiple steps where field names occour twice or more, the input parameter can be extended with @{stepindex} to target the field on a specific step.
formsApi.getFieldValue(fieldName@1)
To get the values of multiple fields at once use getFieldValues. Returns an object with field name as key and value as value
formsApi.getFieldValues(['fieldName1', 'fieldName2'])