Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We  hereby consent to the use in the Prospectus constituting a part of this Registration Statement on Amendment No. 2 to Form S-4 of our report dated March 30, 2021, relating to the financial statements of Pioneer Merger Corp., which is contained in that Prospectus. We also consent to the reference to our Firm under the caption “Experts” in the Prospectus.

/s/ WithumSmith+Brown, PC

New York, New York

September 30, 2021