I'm trying to find a way to convert two booleans into a case when expression

The question is: how can i use two statements in a case when? I'm trying to find a way to make this select statement work. I'm writing code to see if there is contactinformation in a specific code (A01). A filter in the where clausule isn't enough because it's a joint source, I get too many results.

SELECT , (CASE WHEN ("concat"("abs"."waarneming_waarnsrt_code", "abs"."waarneming_waarnsrtreden_code") = ('A01') AND ("abs"."contact_contactsrtcode_telnr_telnrsms_emailadres" like '%@%') then 'email/telefoon in voormelding' end) emailtelefoon , (CASE WHEN ("concat"("abs"."waarneming_waarnsrt_code", "abs"."waarneming_waarnsrtreden_code") = ('A01') AND ("abs"."contact_contactsrtcode_telnr_telnrsms_emailadres" like '!%@%') then 'geen email/telefoon in voormelding' end) emailtelefoon

FROM "abs" INNER JOIN "c"nrs" "nrs" ON ("nrs"."barcd" = "abs"."barcd")

WHERE (("concat"("abs"."waarneming_waarnsrt_code", "abs"."waarneming_waarnsrtreden_code") = ('A01')) AND ("nrs"."year" = '2022') AND ("nrs"."collodata_product_productoptie_kenmsrtcode_optiesrtcode" LIKE '%021;020%') AND ("concat"("nrs"."waarneming_waarnsrt_code", "nrs"."waarneming_waarnsrtreden_code") = ('J23')) AND "week"("nrs"."waarneming_waarndt") > 17)

Group by 1,2 ORDER BY 1 ASC ;