Neither is pressuring the Vice President not to certify the election, but they explicitly state it to be an official act. Page 31 of the ruling:
> Whenever the President and Vice President discuss their
official responsibilities, they engage in official conduct. Pre-
siding over the January 6 certification proceeding at which
Members of Congress count the electoral votes is a consti-
tutional and statutory duty of the Vice President.
> The indictment’s allega-
tions that Trump attempted to pressure the Vice President
to take particular acts in connection with his role at the cer-
tification proceeding thus involve official conduct, and
Trump is at least presumptively immune from prosecution
for such conduct.
They're laying out an extremely permissive standard.
> Whenever the President and Vice President discuss their official responsibilities, they engage in official conduct. Pre- siding over the January 6 certification proceeding at which Members of Congress count the electoral votes is a consti- tutional and statutory duty of the Vice President.
> The indictment’s allega- tions that Trump attempted to pressure the Vice President to take particular acts in connection with his role at the cer- tification proceeding thus involve official conduct, and Trump is at least presumptively immune from prosecution for such conduct.
They're laying out an extremely permissive standard.