Did not receive a decision letter with my Spouse Visa- but was approved!

Hello everyone,
Today I received my spouse visa in the mail, or rather the vignette in my passport which reads "D- Partner (standard) followed by my husbands name.
The validity of the visa is from October 30th 2023 to January 28th 2024, I know the location where I need to pick up my BRP when I arrive to the United Kingdom, but I don't know when as I never received a decision letter, should I have received a decision letter as my BRP will be for 2.5 years.

I have read on various forums I should have received one in order to show immigration/or the post office requires it.
From what I understand, even though I set the expected arrival date on my application as November 1st 2023, I have until January 28th which is when my vignette expires to collect my BRP at the post office ( I am aiming to get to the UK mid january as I'm currently caring for my pet after an intense surgery)

What should I do??? and please tell me if I have anything wrong here, our lawyer also told us we had 90 days for BRP Collection but mentioned but was of the impression I don't need a decision letter. If I do, who should I contact? Anyone else experience this?

Update, just in case anyone else goes through the same thing, yes, I was supposed to receive a BRP letter. They now come by email only so they will not come in the mail with your passport. They advise to wait 3 days before contacting but if you run into the same thing just send an email with your GW reference number and name, nationality, type of visa applied for and so on to here and you should be able to get it.  brpletterrequests@fcdo.gov.uk

I did also end up contacting UKVI but they just re routed me to the email address listed above.