How to modify v:char

[Freed-Wu]

    workspace.registerAutocmd({
      event: 'InsertCharPre',
      pattern: '<buffer>',
      arglist: ['v:char'],
      callback: (character) => {
      }
    })

will

:au InsertCharPre
--- Autocommands ---
coc_dynamic_autocmd  InsertCharPre
    <buffer=3>
              call coc#rpc#notify('doAutocmd', [5, v:char])

However, I want to modify v:char. Change character will not work:

    workspace.registerAutocmd({
      event: 'InsertCharPre',
      pattern: '<buffer>',
      arglist: ['v:char'],
      callback: (character) => {
        character = ''
      }
    })

exe vim command cannot, too.

    workspace.registerAutocmd({
      event: 'InsertCharPre',
      pattern: '<buffer>',
      arglist: ['v:char'],
      callback: (character) => {
        workspace.nvim.command("let v:char = ''");
        workspace.nvim.executeLua('vim.v.char = ""');
      }
    })

How to do something like

autocmd InsertCharPre <buffer> let v:char=''

?

Thanks!

[Freed-Wu]

OK, this work for me:

      arglist: ['v:char', "execute(\"let v:char = ''\")"],
      callback: async (character, _) => {