There are many similar posts, especially for Macs. Maybe this will help someone on Windows. I’m using a Windows PC, standard US keyboard, Anki Desktop, and need to be able to enter grave accents in the cards.
Some applications allow creating (for example) grave accents using Ctrl-` (Ctrl-backtick), then typing the letter. This doesn’t work in Anki, or even in this forum editor. But I can keep an Outlook email editor window open and type my word there, e.g. stràc, then copy and paste it into Anki. It works in the card editor, the browser search, and the forum at least. [I wonder if that accent on the ‘a’ will appear properly after I post this.]
If you create a card with the accent, it won’t be found in Search results unless using the same copy/paste trick, which is a bit of a pain when just doing a search. But the Anki manual has the workaround for this, which is actually nifty because I often don’t remember the accents. Prefix the search string with “nc:” Example: “nc:strac” will find “strac”, with or without the accented “a”.
New Anki using; love this tool.