How to post empty array for multi select

[ak-14]

I am using Tomselect with <select multiple> element in a form. When I deselect all items and submit the form i expect an empty array to be submitted but instead no value is submitted for the select. Is there a way to configure Tomselect to post an empty array when no items are selected?

Thanks

[Mepcuk]

@ak-14 mayne need this field send optional? Can you describe your use case?