How solve the issue of the NERDTree icons displaying incorrectly?

Question

When I configured my init.vim of the neovim on my Linux Ubuntu 22.04, I simply copied the file from here, which uses the NERDTree shortcuts as follows:

nnoremap <C-f> :NERDTreeFocus<CR>
nnoremap <C-n> :NERDTree<CR>
nnoremap <C-t> :NERDTreeToggle<CR>

let g:NERDTreeDirArrowExpandable="+"
let g:NERDTreeDirArrowCollapsible="~"

But when I use the shortcut Ctrl+T to toggle the :NERDTreeToggle function, the display was erratic:

and

But the desired outlook should be as follows:

and

I tried adding :set encoding=UTF-8, but it still didn't display properly. Can anyone help?