I really think I did it before but I just tested and its weird.
If I do a simple one like this it works for me
<a href="arcgis-survey123://?itemID=507ff4ee69b84e0eb2f2db541323e5f2">Launch Form</a>
But as soon as I add a field push like this arcgis-survey123://?itemID=507ff4ee69b84e0eb2f2db541323e5f2&field:PointID={PointID} it just shows as text.
If I try to encode the URL I get a link but it will not launch anything.
I am not sure what is going on here really. If you do not need to pass a field though it should work.
Maybe someone else knows how