Right but until Congress raises the debt ceiling, the Executive Branch has an empty wallet and maxed out credit card. Funding doesn’t go out all at once either. Some programs don’t start until later in the year for example. They typically aim to distribute 1/12th of the yearly allowance per month. Sometimes agencies will over spend early and have to be austere later (like FEMA last year).

Appropriations is Congressional and specifics how much an agency will get over the fiscal year.

Apportionment is under the Executive and addresses when and how those funds are made available.

They are two distinct things.