Yes, "procedure" is the correct spelling.
Initiative procedure.
The word is spelled procedure, just as you spelled it.
It is spelled amendment. And there are 27 total.
25 amendment
trial procedure.
Amendment 25, section 2, established a procedure for filling a vacancy in the vice-presidency.
The twelfth amendment of the Constitution is to provided the procedure of electing the President and Vice President.
Legislation. The procedure for doing this is spelled out in Article I of the Constitution.
Under which category does this Constitutional Amendment fall? procedure to fill a vacancy in the vice presidency
The procedure of electing a president or vice president.
the amendment to the U.S. Constitution places limitations on police interrogation procedures