I can help define that, but I can’t directly change this current published part from here because you don’t have edit access to it, and the right move is to work in your own copy instead. When a user doesn’t have edit access, the recommended flow is to use a new project or a fork/clone link with a pre-filled prompt
Also, one important constraint: for a part project, the terminal count must match the datasheet exactly, and for parts with more than 20 pins, the symbol should usually be split into sub-symbols rather than arbitrarily changing the count. The guidance explicitly says never guess pin numbers, match pin count exactly, and use sub-symbol grouping for complex parts
So if by “make it 21 pins both sides” you mean:
visual layout only: 21 terminals on the left and 21 on the right, for a 42-terminal symbol
actual part definition: change the part so it has 42 total terminals
those are very different.
For a complex IC-style part, the recommended grouping is:
exact datasheet pin count
dedicated power sub-symbol
other pins grouped by function
about 5–15 pins per sub-symbol for readability
If you want, use this fork link to make your own editable copy of the current part and continue there: