I have s24 canda but no 5g antennae When I see videos there is part under the power button. But mine not have ?Any idea

I have heat problem in my s20 then I send yesterday to Samsung service Then they call me today  To take my s20 and thay say the problem solved But  its not Then after 6 hours thay take approval to refund  Then thay gave me a paper to receive my mony ...