Google Chrome has a very nice tool built in it that lets you inspect the page.

In Chrome right-click the page and select Inspect.
On a Chromebook open Chrome and press CTRL-SHIFT-I (not the numeral one).

Then at the top click Sources.
On the left side of the Inspection you will have a list.
Sometimes it will give you the URL outright.
On an item that doesn’t list a URL hold your mouse over the item. A popup might give you the URL. If not, open that item by clicking the triangle on the left and hold your mouse over one of the sub-items.

If the font has changed in your Yahoo Mail. Then as far as I understand, after inspecting the Yahoo Mail web page, Yahoo uses the following fonts in the following order depends on what font is on your system

YahooSans
Helvetica Neue
Segoe UI
Helvetica
Arial
Lucida Grande
sans-serif

If you installed any new fonts recently on your computer delete the ones that match the names above. Be careful what font you delete. ONLY delete the ones you installed. Don’t delete Segoe UI and Arial because it came with Windows. If you accidently replaced an existing font then try to copy the original font from another computer.

For Intel Motherboards

Go in the BIOS
Select Advanced Mode
Go to Settings / Miscellaneous
Enable – Intel Platform Trusted Technology

https://docs.microsoft.com/en-us/office/vba/api/excel.application.onkey

Example: Application.onkey {BACKSPACE}, “”
when Backspace is pressed, it is told to do nothing because of the double quote at the end

List of Shortcuts

https://support.microsoft.com/en-us/office/keyboard-shortcuts-in-excel-1798d9d5-842a-42b8-9c99-9b7213f0040f

https://www.mrexcel.com/board/threads/disable-the-keyboard-shortcuts.111238/