1108.02(b) Verification and Date of Execution 
The verification must be properly signed. See 37 C.F.R. §2.89(a)(3),(b)(3). See 37 C.F.R. §2.193(e)(1) and TMEP §611.03(a) regarding who may sign a verification. If the extension request is unsigned or signed by the wrong party, a properly signed substitute verification must be submitted before the expiration of the deadline for filing the statement of use. 37 C.F.R. §§2.89(a)(3), (b)(3).
If the extension request is not filed within a reasonable time after its execution, the USPTO may require a substitute verification or declaration under 37 C.F.R. §2.20 that the applicant has a continued bona fide intention to use the mark in commerce, for a trademark or service mark, or that the applicant has a continued bona fide intention, and is entitled, to exercise legitimate control over the use of the mark in commerce, for a collective or certification mark. 37 C.F.R. §2.89(h); see TMEP §804.03 (defining a "reasonable time" for filing after execution of documents submitted in a Section 1 application).
See TMEP §§611-611.06(h) regarding signature on correspondence filed with the USPTO.