How is a beyond-use date set for compounded cagrilintide in 0.9% sodium chloride?

Details up front: cagrilintide · 0.9% sodium chloride.

I would like to understand the steps well enough to explain them to someone else.

I have access to a refrigerator with a logger and a freezer without one, which may be relevant.

So: what is the actual procedure, and which steps matter as opposed to being ritual?