in otrs: How to show a dynamic field checkbox in a template as a checked checkbox

I've a dynamic field checkbox that can be selected during a process in otrs. At the end of the process a mail have to be sent with a template inside that summarize the information collected in the process stored in multiple dynamic fields, the only one that I can't figure out how to show as a checked/unchecked checkbox is... the checkbox. If I poit on

I'm workin in this enviroment: Erizone 5.3.0 on OTRS 5.0.25

If I point on [code][/code] I receive as result [code]1[/code]

If I point on [code][/code] I receive as result [code]Checked [/code]

I want to show at least a mark when the checkbox is checked