How I can switch from working offline to working online in outlook?

Thank You!

On my computer Windows 11. I am using Microsoft 365 Outlook. I am not using the Outlook.com. Just regular Outlook. At the top of the screen, there is not a tab or anything which says work online or work offline. Also there is not a "Preferences" section.

In Old Outlook, in the up top across the screen area where there's things such as Send and etc, go to the far right, there's a button there Work Offline. Press that and it should switch to Work Online, or grey over to show if Offline or Online... grey Offline, white Online from memory.

Up on the top menu area that runs across the screen, there is a button on the far upper right that says Work Offline or Work Online, press on that. I found with my problem with that (oh and that's in Old Outlook, don't know where it is in New Outlook), I had to hold and press which I thought was odd but finally that unstuck it! Mind you, it keeps locking on Work Offline, not sure why. Most of the time when I press that button it switches to Work Online, but not always.

Wondering whether or not deleting, uninstalling and reinstalling Old and New Outlook or Mail will lose all the emails within them and etc.?