Disable Open, Copy and Delete buttons based on a record column

Hello,

I want to disable the open, copy and delete button for the records in which a lookup column has a certain value. Example: only diable the buttons when the case category is "Incident".

I tried to use a query to get that lookup value but I need to use the read value outside the query in order to call the base fuction (this.callParent(arguments)) if the disable condition is not matched.

I hope you can offer me a solution. Thank you in advance!