Payment In GST Delayed

Dear experts..i got a query which is like if we provide services to any organization and the payment against service we receives after 2-3 months in this case how we would show this in GSTR3B? Like we provided services in May raises Bill against it in the same month and payment of this service would be received in August how would we treat this in GSTR3B return? Should we show this Bill in May GSTR3B return and pay tax without receiving it from the party or organization or should we wait till payment is received then pay tax and file return?

Please answer my query..

Thanks in advance.