Unable to use contains function, getting error

Getting the following error when trying to use contains function with a text field on PostgreSQL:

ERROR: function contains(text, character varying) does not exist Hint: No function matches the given name and argument types. You might need to add explicit type casts. Position: 10094

Hi @random009
Post "Diagnostic Info" from Admin > Troubleshooting.
And include what you are inputting into the Custom Expression.

Hi I was inputting a string such as "category_1" into it but however the field I am comparing it against is a text field in the database, I tried typecasting either of the argument, yet it produces a similar error.