Laravel, Validator check if two columns exist in same table

Question

i have 3 parameters (br_code,slc_code,slt_code) im done with validations for br_code and slc_code

to validate slt_code, i have to check if slc_code and slt_code exist on table(sltype) , how do i do it?

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thankyou

i tried this code but it give me different respond like its storing instead of checking enter image description here