There are some rules for entering sextants, but any relatively rough description will work.
12 12s 12 12w
12 12 12 12
It suffices if there is something other than a number between the large and small numbers. Any case may include lowercase or uppercase letters such as N or S, E or W. about it.
When using sextant input, be sure to be in the target facet or switch to the target facet display.
This is because, for example, when specifying TF, the position of the marker overflows when small vertical and horizontal facets are displayed.