When you use the checkbox you will just get the boolean value of true or false depending on whether the user ticked the checkbox or you have it setup as default etc.
https://www.wix.com/corvid/reference/$w.Checkbox.html#checked
checked
Sets or gets whether a checkbox is checked.
Description
Setting the checked property to true places a check in the checkbox. Setting it to false removes the check from the checkbox.
Getting the checked property returns whether the checkbox is checked or unchecked.
If you are wanting to get some sort of value from that checkbox, then you need to look at using code to add the value as shown here.
https://www.wix.com/corvid/reference/$w.Checkbox.html#value
value
Sets or gets a checkbox’s value.
Description
The value property is not related to whether the checkbox is checked or not. To determine the checked status of a checkbox, use the checked property.
The value property is used for storing a value that is associated with the checkbox.
It is not considered when evaluating the checkbox’s validity and it does not trigger an onChange event when the value is modified.
Even if a checkbox is connected to a dataset, its value property is not related to the value of the collection field it is connected to. The field’s value is determined by the checkbox’s checked property.
Nayeli (Code Queen) has a tutorial about combining checkboxes and their values here.
https://codequeen.wixsite.com/checkboxes
How to combine values in Wix Code - Checkboxes Tutorial
You can look at her code example and modify it to suit your own needs and to collect the value in your dataset and use that instead of the checkbox boolean field
Otherwise, you can look at using checkbox groups which give the user multiple choice and you can set them up to have a label which is shown on the page and a value that is added to the dataset on submit
https://www.wix.com/corvid/reference/$w.CheckboxGroup.html
CheckboxGroup
Checkbox groups are used for selecting any number of the given options.
Checkbox groups consist of a list of options . Each option contains a label, which is what the user sees, and a value, which is what is used in code and stored in your collections.