Monitor for computer (Westham, Weymouth DT4)

Acer LCD monitor V206HQL, as bought new 2017 Oct 20 for £72; with original power cord that has AC adaptor.
Still full working order, but as it does not have HDMI connection (though its website and paperwork say it does!), I cannot use it with my new Windows 11 computer. (Would work with a Windows 10 computer.)
It is diagonally across 53 cm / 21”. On label on it box, it says Display size 19.5”/49 cm.