%% You should probably cite rfc9290 instead of this I-D.
@techreport{ietf-core-problem-details-00,
    number =    {draft-ietf-core-problem-details-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-core-problem-details/00/},
    author =    {Thomas Fossati and Jaime Jimenez and Klaus Hartke},
    title =     {{Problem Details For CoAP APIs}},
    pagetotal = 13,
    year =      ,
    month =     ,
    day =       ,
    abstract =  {This document defines a "problem detail" as a way to carry machine- readable details of errors in a CoAP response to avoid the need to define new error response formats for CoAP APIs.},
}