Cancel and Go Back Button

Hi Everyone, I'm new to Quickbase and could use some help.

I'm building an application with two related tables:

• Price Request (Header Table)
• Attachments Table (Each Price Request can have multiple attachments)

I've created a form in the Price Request table with an "Add Attachment" button that routes users to the Attachment form, allowing them to upload documents. Here's the formula I'm using for that:

URLRoot() & "db/" & [_DBID_ATTACHEMENTTABLE] & "?a=API_GenAddRecordForm&_fid_7=" & URLEncode([Record ID#]) & "&z=" & Rurl()

Now, I want to add a "Cancel and Go Back" button on the Attachment form that:

1. Deletes the current attachment record.
2. Redirects the user back to the related Price Request record.

Here's the formula I tried:

URLRoot() & "db/" & Dbid() & "?a=API_DeleteRecord"
& "&rid=" & URLEncode([Record ID#])
& "&apptoken=APP_TOKEN"
& "&rdr=" & URLEncode(
    URLRoot() & "db/" & [_DBID_PRICEREQUESTTable] & "/form?a=dr&rid=" & [Related Price Request])

But I’m getting this error:

<qdbapi> <action>API_DeleteRecord</action> <errcode>30</errcode> <errtext>No such record</errtext> <errdetail>Missing "rid" parameter.</errdetail> </qdbapi>



In the picture below(Attachment Form) 

Field Pricing Request ID  is a lookup field from Price Request Table(Related Price Request)
Field Price Request - Status is a look up field from Price Request Table