Code point
U+3346
Glyph appearance depends on your fonts.
U+3346
So<square> 30DE 30EB 30AFU+3346 SQUARE MARUKU is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the CJK Compatibility block.
Choose the representation you need, then copy its value.
U+3346
13126
㍆
㍆
E3 8D 86
3346
00003346
%E3%8D%86
\u3346
\u3346
\u3346
\3346