Hello.
this feature is exist at the Business Medium versions.
At that version for configuration of this feature you are need to set the cost per day at the General Booking Settings page at the Cost settings. Then at the Booking > Resources > Advanced cost page you can specify this additional cost per visitors selections:
1: 100%
2: 20/day
3: 40/day
4: 60/day
You can test live demo of that version to be sure in functionality and do not have misunderstanding. Yo can also upgrade to that version, using the upgrade link at the top right side of the General Booking Settings page
Does this function only work if you use the Select or Checkbox code.
Is there any other codes we can use to add the additional cost features?
Hello.
Its works only with checkboxes or selectboxes at the Business Medium and higher versions.
But if you are need to have the additional cost setted by default, you can use the checked by default checkbox, which is not visible to the visitors, similar to this:
<div style="display:none">
[checkbox* my_tax default:on ""]
</div>
and then configure the additional cost at the Booking > Resources > Advanced cost page.