How do I code to use only one if statement to cater these two values?

I need to get the enum itself first by using RegoDocumentType.getByValue(createOrderRequest.getIdDocument().getIdType())

Then check for null value, if it is not null, it will return the enum value. Else, it will return the createOrderRequest.getIdDocument().getIdType() as default.

So how do I code to only use one if statement to cater for both NRIC/11B and FIN smag value to rego value using RegoDocumentType enum?

Here's my enum:

public enum RegoDocumentType {
    NRIC_11B("NRIC/11B", IdentityType.NRIC.toValue()),
    FIN("Employment Pass", IdentityType.EM_PASS.toValue()),
    ;

    private static final Map<String, RegoDocumentType> BY_SMAG_VALUE = new HashMap<>();

    static {
        for (RegoDocumentType identityType : values()) {
            BY_SMAG_VALUE.put(identityType.getSmagValue().toLowerCase(), identityType);
        }
    }

    private final String smagValue;
    private final String regoValue;

    RegoDocumentType(String smagValue, String regoValue) {
        this.smagValue = smagValue;
        this.regoValue = regoValue;
    }

    public String getSmagValue() {
        return smagValue;
    }

    public String getRegoValue() {
        return regoValue;
    }

        public static RegoDocumentType getBySmagValue(String smagValue) {
        return BY_SMAG_VALUE.get(smagValue.toLowerCase());
    }
}