write variables from custom component to dialog flow

Summary:

context.setVariable('variable_name', value); doesn't work as it should. I have even tried context.variable(), but nothing works. I want to set variable which will store the result value and in dialog flow I can output the result to user using ${variable_name}

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):