4.24 How can I create a drop-down multi-select combobox widget?

Build in combobox is for a single selection. I want make a multiselect widget (drop-down list with checkboxes). What is the proper way to do this?

You should freestyle it. Can you show a video of it?

Freestyle it using the combination of existing widgets.

Thank you for reply. Where can I find information about freestyle widgets?