I own an A12 and set up a single contact on my home screen. Here's what I did, I think: it has been awhile since I did this
1. Long press blank area of home screen and select Widget.
2. Scroll down until you see Direct Dial.
3. You should be asked to select a contact.
4. When you find the person you want, tap on the name.

If that doesn't work, let me know and I will try to set up another contact on my home screen and write down the steps as I go along.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Several hours later after trying to set up another contact on my home screen.
1. Long press blank space on home screen and select widget from the choices at the bottom of the window.
2. My choice is Contacts, rather than Direct Dial. I'm on android 12.
3. I have 3 choices when I open Contacts by tapping on the down arrow: Contact, Direct Dial and Direct Message.
I tapped on Direct Dial and tapped add.
4. My Contacts list opened and I could scroll through and tap which person/business I wanted to appear on my Home Screen

 

Here is what my screen looks like when I
1. Long press blank area of home screen and select Widget.

I have no clue what to do with this screen.
I tried clicking on the tabs and buttons, but all it does is change screens to something else. I don't get any selections for adding phone numbers in single tabs to the home screen.

 

If you click the up arrow aside of recommended, do you then see other choices?

 

I finally figured it out. Went through about 10 Youtube videos before I found one that worked on it.

Thanks!

 

If you can pass the solution along, it may help others in the future. Then ...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
How to mark a thread solved.

Above your first post in this thread, but below the black bar, on the right-hand side, you will see a "kebab" menu (three vertical dots). Click that and select Edit Thread. You will see a drop down in front of the thread title that says "Prefix". Drop that and "Solved" should be one of your options.

Real simple, huh? Who needs a dedicated button that does this in a single mouse click? ;-)