GRANT OF POWER OF ATTORNEY

A. Power of Attorney. Effective as of January 31, 2017, each entity listed on
Schedule A attached hereto, and such additional affiliated entities that shall
come into existence from time to time (each, a "Granting Entity"), hereby
constitutes and appoints Tracy L. Sedlock and Richard H. Zamboldi as its true
and lawful attorneys-in-fact and agent with full power of substitution, in its
name, place and stead to make, execute, sign and file such instruments,
documents or certificates as may be necessary or proper in the normal course of
such Granting Entitys business.

Each Granting Entity hereby further grants to such attorneys-in-fact full power
and authority to do and perform all and every act and thing whatsoever
requisite, necessary and proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as such Granting
Entity might or could do if present, hereby ratifying and confirming all that
such attorneys-in-fact shall lawfully do or cause to be done by virtue of this
Power of Attorney and the rights and powers herein granted, including, without
limitation, the authority to execute documents on behalf of such Granting Entity
in connection with investments made by such Granting Entity or any entity
controlled by such Granting Entity.  Each Granting Entity acknowledges that no
such attorneys-in-fact, in serving in such capacity at the request of the
undersigned, is hereby assuming any of the undersigned entities responsibilities
under the tax laws of the United States, any state or other jurisdiction.  This
Power of Attorney shall remain in full force and effect with respect to each
such Granting Entity from the date hereof until revoked by each respective
Granting Entity in a signed writing delivered to the foregoing
attorneys-in-fact.

B. Consent to Grant of Power of Attorney.  As of the date set forth above, each
of the undersigned persons, individually and in his capacity as a member,
partner or equity holder (each, a "Constituent Member") of a Granting Entity and
as a member, partner, trustee or equity holder of any Constituent Member, hereby
consents to, and causes each such Granting Entity and Constituent Member, to
consent to and cause, the grant of Power of Attorney set forth in Paragraph A
above.

Schedule A GRANTING ENTITIES

Accel London Investors 2016 L.P.
Accel Growth Fund Investors 2016 L.L.C.
Accel Leaders Fund Investors L.L.C.
Accel Growth Fund IV Associates L.L.C.
Accel Leaders Fund Associates L.L.C.
Accel London V Associates L.P.
Accel London V Associates L.L.C.

IN WITNESS WHEREOF, each of the undersigned have executed this Grant of Power of
Attorney or a counterpart hereto as of the date first set forth above.

/s/ Andrew G. Braccia

Andrew G. Braccia in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ Kevin J. Efrusy

Kevin J. Efrusy in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ Sameer K. Gandhi

Sameer K. Gandhi in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ Ping Li

Ping Li in his individual capacity and as member, partner, officer, trustee or
equity holder of every entity that is an equity holder of a Granting Entity

/s/ Arthur C. Patterson

Arthur C. Patterson in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ Tracy L. Sedlock

Tracy L. Sedlock in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ James R. Swartz

James R. Swartz in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ Ryan J. Sweeney

Ryan J. Sweeney in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity

/s/ Richard P. Wong

Richard P. Wong in his individual capacity and as member, partner, officer,
trustee or equity holder of every entity that is an equity holder of a Granting
Entity