How do I send a context to trigger a query rule in Magento?

// Creates a context variable with the category title (algoliaConfig.instant.title)
// We have to format it for the variable to be usable in the Algolia dashboard (we replace everything which 
// is not a letter or a figure by a dash)
// for example : "Pants & Denim" becomes "Pants-Denim" so the ruleContext is "category_Pants-Denim"
function algoliaHookBeforeInstantsearchInit(instantsearchOptions) {
  
  var categoryContext = 'category_'+ algoliaConfig.instant.title.replace(/[^A-Za-z0-9_-]+/g, '-');

  if (typeof instantsearchOptions.searchParameters.ruleContexts === 'undefined') {
    instantsearchOptions.searchParameters.ruleContexts = [categoryContext];
  } else {
    instantsearchOptions.searchParameters.ruleContexts.push(categoryContext);
  }

   return instantsearchOptions;
 }