There "excuse" refers (informally) to the written note, a piece of paper the student hands in to the teacher or to the office. Hence the verb "bring".

A student could say

I left my excuse on the kitchen table.

or

The dog ate my excuse.

There "excuse" refers (informally) to the written note, a piece of paper the student hands in to the teacher or to the office. Hence the verb "bring".

A student could say

I left my excuse on the kitchen table.

or

The dog ate my excuse.

or

I forgot to bring my excuse. I left it on the table.