Make Apple Mail show imap subfolders

On new MacbookPro (Sonoma 14.4), Apple Mail (apparently different from Mail on iPad/iPhone) would not display any of my subfolders, and I have at least 100 for all my clients. I finally made it do it!

Hover over the account name and you'll see a small + and ^ appear. Click on the + and it asks for the name of the folder. I typed in a short, existing one called 'ASD' and it added it as a subfolder in my account AND pulled in via imap ALL the other folders I was looking for, and this included sub and sub-subfolders. I'm back in business after leaving my 35 years of work on Windows Outlook and moving to a Mac. Onward and upwards!