By default, data format will follow the end-user's default locale or from their personal setting in Salesforce, You can change the locale format by edit the Data Formatter in the template file.
The checkbox field in Salesforce has Boolean type values. By default, Boolean values appear as "true" and "false". Thus, when the box is checked, the field value is "true", and when unchecked it is "false".
You can change the content in the document into other text, for example "Yes" to replace "true" and "No" to replace "false"
In Settings tab -> Salesforce Data -> Data Formatter
Click the Modify button next to Boolean formatter
Give the new text you want to be replace for "true" value in True String, and text to replace for "false" value in False String