Send slash command with options

[vined-underscore]

When I try sending a slash command that has no options like /bump, it works fine, but I have no idea how to send commands with options like /say text:.
This is what I've tried:

@vbot.command()
async def send(self, ctx, *, msg):
  channel = ctx.channel
  async for slash in channel.slash_commands(
    query = "say",
  ):
    await slash(data = {
      "name": "say",
      "text": msg
    })

I looked in the source code and saw I needed to pass in the data argument but when I try running that command I get this error:
discord.errors.HTTPException: 400 Bad Request (error code: 50035): Invalid Form Body In data.options: Missing interaction application command option