The IRS's Right to Retain Representation
IRS Publication 1, entitled "Your Rights as a Taxpayer" (https://www.irs.gov/forms-pubs/about-publication-1), includes a full list of taxpayer rights. One of these rights is the Right to Retain Representation.
You may select a representative, such as an attorney, CPA, or another authorized person, to represent you in an interview with the IRS. Your representative can attend the IRS interview on your behalf, and you do not need to attend with your representative.
You must prepare Form 2848, Power of Attorney, to designate your representative(s). The representative(s) you select must not be disbarred or suspended from practice before the IRS.