The article you linked to,  How do I add accommodations for a student in New Q... - Instructure Community - 1092 , seems to have been recently updated.  This is a change in the workflow and very bad timing just before the end of the semester!

The way we used to add time was to go to Moderate in any quiz, select the pencil icon by a student's name, and select time multiplier. It would apply to all quizzes in the course.

The new workflow is to go to Moderate in any quiz, select the student's name, and select time multiplier. It will apply to all quizzes in the course.

This is the kind of small change that is frustrating and unnecessary.