CONFIRMING STATEMENT

This Confirming Statement ("Statement") confirms
that the undersigned, Yuki Whitmire, pursuant to her
power and authority in her role as attorney-in-fact for
Carrie Lee Kirby ("Reporting Person") granted by that
certain Confirming Statement entered into as of October 6, 2020,
hereby authorizes, directs and designates Daniela Gutierrez ("Designee"),
acting singly, to: (1) prepare, execute in the Reporting Person's
name and on the Reporting Person's behalf, and submit to the
U.S. Securities and Exchange Commission (the "SEC") a Form ID,
including amendments thereto, and any other documents
necessary or appropriate to obtain codes and passwords enabling the
undersigned to make electronic filings with the SEC of reports
required by Section 16(a) of the Securities Exchange Act of 1934
("Exchange Act") or any rule or regulation of the SEC;
(2) execute for and on behalf of the Reporting Person, in the
Reporting Person's capacity as an officer and/or director of V
istra Corp. (the "Company"), Forms 3, 4, and 5 in accordance with
Section 16(a) of the Exchange Act and the rules thereunder;
(3) do and perform any and all acts for and on behalf of the
Reporting Person which may be necessary or desirable to complete
and execute any such Form 3, 4, or 5, complete and execute any
amendment or amendments thereto, and timely file such form with
the SEC and any stock exchange or similar authority; and
(4) take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of the Designee, may be of,
benefit to, in the best interest of, or legally required by, the
Reporting Person, it being understood that the documents executed
by the Designee on behalf of the Reporting Person pursuant to this
Statement shall be in such form and shall contain such terms and
conditions as the Designee may approve in the Designee's discretion.

The undersigned, pursuant to her power and authority in her role
as attorney-in-fact for the Reporting Person, hereby grants to
the Designee full power and authority to do and perform any
and every act and thing whatsoever requisite, necessary, or
property to be done in the exercise of any of the rights and powers
granted under this Statement, as fully to all intents and purposes as
the Reporting Person might or that the Designee, or the Designee's
substitute or substitutes, shall lawfully do or cause to be done by
virtue of this Statement and the rights and powers herein granted. On
behalf of the Reporting Person, the undersigned acknowledges that
the foregoing Designee, in serving in such capacity on behalf of the
Reporting Person, is not assuming, nor is the Company assuming, any
of the Reporting Person's responsibilities to comply with
Section 16 of the Exchange Act.

The authority of the Designee under this Statement shall continue
until the Reporting Person is no longer required to file
Forms 3, 4, and 5 with respect to the Reporting Person's
holdings of and/or transactions in securities of the Company,
unless earlier revoked by the Reporting Person, or any
attorney-in-fact, in a signed writing delivered to the Designee.

IN WITNESS WHEREOF, the undersigned has caused this Statement
to be executed as of this 26th day of February, 2024.

    By: /s/ Yuki Whitmire, as attorney-in-fact for
Carrie Lee Kirby
    Name: Yuki Whitmire