[Home](./index.md) > [sip.js](./sip.js.md) > [SessionDialog](./sip.js.sessiondialog.md) > [refer](./sip.js.sessiondialog.refer.md) ## SessionDialog.refer() method REFER is a SIP request and is constructed as defined in \[1\]. A REFER request MUST contain exactly one Refer-To header field value. https://tools.ietf.org/html/rfc3515\#section-2.4.1 Signature: ```typescript refer(delegate?: OutgoingRequestDelegate, options?: RequestOptions): OutgoingReferRequest; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | delegate | OutgoingRequestDelegate | | | options | RequestOptions | Options bucket. | Returns: `OutgoingReferRequest`