enter_start_frequency.js

var defaultValues = {
    startFrequency: 1234,
    selectedOption: "opt2"
};

var values = await input({
    title: "Enter Start Frequency",
    fields: [
        { 
            name: "startFrequency",
            displayName: "Start frequency",
            type: "number"
        },
        { 
            name: "selectedOption",
            type: "enum",
            enumItems: [
                {
                    id: "opt1",
                    label: "Option 1"
                },
                {
                    id: "opt2",
                    label: "Option 2"
                },
                {
                    id: "opt3",
                    label: "Option 3"
                }
            ]
        }
    ]
}, defaultValues);

console.log(values);