誕 is a Japanese kanji written with 15 strokes, listed here under the keyword “nativity”. It is built from 延 (prolong) and 言 (say). In Remembering the Kanji by James W. Heisig it is frame 420.
On KumiJi Glyph Explorer, open the parts search and type “prolong” + “say”. 誕 is among the results, together with every other character containing the same shapes.
Open 誕 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.