How to pass NULL value in webservices object repository

Hi Team,

I’m new to the Katalon studio and I have a question about the Webservices object repository. We are using GraphQL. Could you please let me know how to pass a NULL value in the HTTP Body?

{ “filter”: {
“search_keyword”: ${search_keyword}
“limit”: ${limit}

I need to pass search_keyword = null.

null is a valid JSON value.

Quote: A value can be a string in double quotes, or a number, or true or false or null, or an object or an array. These structures can be nested. More here.