堵 is a Japanese kanji written with 11 strokes, listed here under the keyword “railing”. It is built from 土 (soil) and 者 (someone). In Remembering the Kanji by James W. Heisig it is frame 2306.
On KumiJi Glyph Explorer, open the parts search and type “soil” + “someone”. 堵 is among the results, together with every other character containing the same shapes.
Open 堵 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.