Search by event custom fields

sorry but this isn’t available at the moment.

According to this tutorial it is

https://wp-events-plugin.com/tutorials/adding-custom-event-search-form-fields/

yes, however you might want to follow/read the whole tutorials for more details – https://wp-events-plugin.com/tutorials/creating-a-events-manager-add-on-a-complete-walkthrough/

for the source code of that tutorial: https://d1mkunav5pg7l3.cloudfront.net/wp-content/uploads/2011/04/em-event-styles.txt