apply_filters( 'relevanssi_wildcard_search', boolean $use_wildcards )
This filter enables wildcard matching.
Parameters
$use_wildcards
(boolean) If true, it enables wildcard matching. Default false.
More information
When this filter returns true, Relevanssi Premium supports wildcard matching. You can then use * to match zero or more characters and ? to match exactly one character.
add_filter( 'relevanssi_wildcard_search', '__return_true' );