How to remove single URL from FF autocomplete

Linux Firefox stores cached autocomplete URLs in:

~/.mozilla/firefox/[profile]/places.sqlite

So, install some SQLite tool like:

sudo apt install sqlitebrowser

close FF and then open this file:

sqlitebrowser places.sqlite

then choose right table:

select row with URL you hate and kill it:

Save database, close programme and copy places.sqlite back to your profile.