klegeni fu'ivla

x1 has x2 (ka) as their gender; x1 identifies as gender x2.

From -kle- (< klesi) and the ending of trangeni, singeni. The -geni ending is ultimately from Latin genus and its descendants (cf. English gender).

In notes:

jenri
x1 is the gender (social, not biological sex) of x2.
sekse
x1 is the biological sex (male, female, or otherwise) of x2.