ConfiMap/Secret mount to gateway

I installed my gateway with gateway helm chart. I’m not seeing an option to add there custom volumes. I tried to mount my configmap and secret by adding bellow annotations in value.yaml to podAnnotations to update gateway deployment, but it doesn’t look like it works. Is there any other possibility to achieve what I need? IstioOperator maybe? If possible, i want to stick with gateway helm chart. '{"token-secret":{"secret":{"secretName":"token-secret"}},"hmac-secret":{"secret":{"secretName":"hmac-secret"}}}' '{"token-secret":{"mountPath":"/etc/istio/oauth/token-secret.yaml","readOnly":true},"hmac-secret":{"mountPath":"/etc/istio/oauth/hmac-secret.yaml"}}'