sql server – Understanding triggers in Azure SQL database

I have set up a trigger on a table in an Azure SQL database. This trigger is configured to fire on INSERT operations, and it triggers a stored procedure whenever an insert occurs.

I would like to understand the behavior when inserting multiple rows into the table using a single INSERT statement, like in the example below:

INSERT INTO table
SELECT 1, 2
UNION
SELECT 3, 4
UNION
SELECT 4, 5;

In this case, will the trigger (and subsequently the stored procedure) execute only once for the entire INSERT statement, or will it execute three times, once for each row inserted?