Exhibit 23.3

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the use in this Registration Statement on Amendment No.1 to Form S-4 of our report dated March 31, 2021, relating to the financial statements of Switchback II Corporation, which is contained in that Registration Statement. We also consent to the reference to us under the caption “Experts” in the Registration Statement.

/s/ WithumSmith+Brown, PC

New York, New York

June 22, 2021