MongoDb taking time in saving document on production

Question

I am saving a mongo document using mongotemplate in java spring boot. But sometimes it is taking time to save the document. usually it is taking 2 Min to save the document. I have checked in the mongo server graphs, during that time pageout seems to be increase. I am having t2.medium aws server. Graph Reference of mongo db server is attached(See the Page OUT spike 13376). please suggest what should I do to sort this page OUT issue...

below is the java code to save the document:

public <T extends BaseMongoEntity> T save(T objectToSave) {
    return mongoTemplate.save(objectToSave);
}

Below is mongo entity:

@Data
@Document(collection = MDBCollection.WALLET_TRANSACTION)
public class WalletTransactionRequest extends BaseMongoEntity {

    @Serial
    private static final long serialVersionUID = 2773733474298691321L;

    private String orderCode;
    private String awbNo;
    private String tenantCode;
    private List<OperationRequest> operationRequestList = new ArrayList<>();
    private boolean preValidateBalance = false;

    @Data
    public static class OperationRequest{
        BigDecimal amount;
        BigDecimal gstAmount;
        WalletOperation walletOperation;

        public OperationRequest(BigDecimal amount,BigDecimal gstAmount, WalletOperation walletOperation) {
            Objects.requireNonNull(gstAmount, "GST rate cannot be null");
            this.amount = amount;
            this.gstAmount = gstAmount;
            this.walletOperation = walletOperation;
        }
    }

    public void addOperation(OperationRequest operationRequest){
        this.operationRequestList.add(operationRequest);
    }

    public WalletTransactionRequest(String orderCode, String awbNo, String tenantCode) {
        this.orderCode = orderCode;
        this.awbNo = awbNo;
        this.tenantCode = tenantCode;
    }
}