How to add tags to labels in the Side panel?

How to add something like “beta” here? This is found in the default theme

This block in the default has nothing special that can make this tag. This is its code in manifest.json:

{
"label": "request_list_group_label",
"variables": [
	{
		"identifier": "request_list_beta",
		"type": "checkbox",
		"description": "request_list_beta_description",
		"label": "request_list_beta_label",
		"value": false
	}
	]
},

And the translation is also nothing special: